|
|
Post by Bullshop on Jul 29, 2023 9:55:57 GMT -7
Yesterday I worked a little bit toward finding a subsonic load for the 30-06. I dont really know why other than I had read of a couple people inquiring as to loads for such. Some years ago I acquired an iron NEI six cavity mold for a 230 grain semi pointed boat tail bullet without lube grooves just smooth. These drop from the mold at .307" diameter so are perfect for powder coating. From my experience with black powder cartridge rifles in learning what nose shapes work best for long range shooting at subsonic I now understand this bullet is the perfect shape for long range in flight stability and being best at resisting wind and atmospheric drag. For what ever reason the shapes that are most efficient at supersonic velocity do not work well at subsonic velocity.
Our best and most efficient supersonic shapes have long slender ogives with pointed nose putting the balance point well to the rear of the bullet but in subsonic flight the more efficient shapes have the balance point farther forward with a more blunt nose shape.
So anyway having what seemed to be the perfect cast bullet design for 30 caliber subsonic flight I thought to try to work up a good subsonic load in a 30-06. Why a 30-06 ? Well because there are commercially available subsonic loads for the 308 and the 300 BO so no gain there but from what I see there are no subsonic loads available for the 30-06. Another good point I want to point out about the old NEI bullet design is that even though is a heavy bullet at 230 grain because of its short ogive and semi pointed nose shape for comparatively short length it will stabilize at subsonic velocity even in the standard 30 caliber rifling twist rate of 1/10" so usable in a large variety of guns and not just those with the fast 1/7" twist of the 300 BO intended for the long VLD bullets designed for supersonic flight.
OK so now that I have gotten my point across I will shorten this up by leaving out the developmental details and just go to the final load. Having only one 30-06 rifle for testing an old Rem model 30 Express with iron sights I was likely lacking in precision test equipment but it did allow us to get loads in the 2 moa area at the 100 yard test range.
The final test load settled on was 10.5 grain of Trail Boss powder giving an average of 1110fps velocity. I thought that about perfect but then considered the variables involved with the speed of sound so have modified my preference to 10 grain TB to be better suited to a wider range of elevations as well as temperature's. With cold temps and low elevations the 1110 velocity average may in some cases be supersonic. For us here in MT at 6000 ft elevation and more moderate temps 1110 is good but sometimes I forget that not everyone lives here.
Anyway that was an interesting adventure for a Friday and was fun and I learned something. Oh yea one other little thingy that turned up was that I discovered that in this test that large pistol primers gave the most uniform ignition which is exactly oposite of what I thought would be the case. The mildest primer tried gave the best results, who woulda thunkit !
|
|
|
|
Post by missionary on Jul 29, 2023 13:43:10 GMT -7
That was interesting ! A 230 at 1100 fps is going to do serious work on thin skinned critters.
We have played with .312 RB a little and it was easy to get a "bunny load" that was accurate enough to head shoot our garden robbers. I do not remember the load but was about 3 grains Unique. Did not try pistol primers. Had no idea to try that. Rifle is a Mauser Mark X 1-10 twist 24" hammer forged. We did lift the muzzle before each shot to settle the powder on the primer.
|
|
|
|
Post by Bullshop on Jul 29, 2023 16:18:28 GMT -7
With the very bulky for weight Trail Boss powder a 10.5 grain charge was filling about 70% of the 30-06 case so there was no need for filler or to raise the muzzle before each shot. This is a very low noise level load because the fast powder burn rate and small volume of powder are completely consumed within the 24" barrel so there is also near zero muzzle flash. That and the fact that there is no supersonic crack of the bullet breaking the sound barrier makes it a very sedate sounding load but as you said I wouldn't want to stand in front of a 230 grain bullet travelling just under the speed of sound. BTW if you estimate the speed of sound to be 1050 fps plus the temp in Fahrenheit you will be pretty close not considering elevation. Higher elevations have less dense atmosphere so allow sound to travel slightly faster than at sea level. At 1050 plus a 70* F degree day at my elevation has sound moving at about 1120 fps so this load at 1110 fps is good for a suppressor but if that temp drops to 50*F my 1110 fps load is now supersonic. That is why I said its better to drop the load to 10gn and cover a wider range of conditions.
|
|
|
|
Post by missionary on Jul 30, 2023 3:12:40 GMT -7
Trail Boss does seem to accomplish the desired task of being bulky yet soft on the shoulder.
I seem to have seen a caliber .30 MG report that dealt with the lethalety of the 173 BTSP. It was written to deal with max ranges the MG crews could expect the projectile to still be capable of uniform /torso penetration. The range is not the need to my subsonic thinking but it seems it was around 650 fps that impacts were determined to no longer be 90% effective on soft stationary targets.
So makes me wonder at what FPS that 230 grain would still be capable of a complete broadside chest cavity strike on a corn cruncher ? I would think at 300 yards it would still have all the momentum necessary to accomplish the task. And very quiet in getting there even without a sound tool.
Oh the fun of running experiments with direct fired flying objects
|
|
|
|
Post by Bullshop on Jul 30, 2023 6:51:35 GMT -7
I am not sure but think that many ballistic programs use lag time to compute trajectories. The way I understand it lag time is based on the percentage of velocity loss from the muzzle to any given range. It seems so interesting to me that supersonic projectiles have a higher lag time than does a subsonic projectile of the same weight and shape. Also a supersonic projectile when dropping to below the speed of sound will pass through an area of turbulence that can result in a slight change of course after going subsonic. If a ballistic task can be accomplished with a subsonic projectile it may be advantageous to keep its entire flight subsonic. That plus the fact that a subsonic projectile can be sound suppressed to the point of being nearly silent. This was the whole idea behind the development of the whisper cartridges one commercial version being the 300 BO. The idea was not new to the whisper cartridges but started in WW-2 with the Delihle conversion of the SMLE rifles to 45 acp a subsonic round. The development of the whisper cartridges the 300 and 500 were to enhance the potential range of the sound suppressed rounds.
The purpose of the Delihle was a means to silently neutralize sentries in advance of an attack on a fortified position but as said for the precise shot placement required the 45 acp had a very limited range. The development of the whisper cartridges effectively multiplied that range several times over for the same intended purpose.
The 300 BO was the commercial offspring of that development but most people that bought them bought them for the advertising hype and really had no clue of its true purpose. The 300 BO came on the scene with a bang then left just as fast. I always felt it was a good turn from the bigger is better the market had been promoting the gave us a few generations of flinch inducing super magnums. The little 300 turned us from Weatherbyitis to the realization that 30-30 ballistics have a lot of capability. From there we moved on to the Creedmoor cartridges that are far easier for most people to shoot well than any ultra mag. I applauded the turn the industry made because as a guide I saw what the effects of magnumitis can be.
|
|
|
|
Post by todddoyka on Jul 30, 2023 9:51:16 GMT -7
Yosemite Sam says " i's hates magnumitis!!!!" and so do i. i've used Trail Boss in most of my rifles. TB was great for the 444 Marlin. i had some 200gr Hornady XTP (25 - 30 of them) that i loaded up some TB and let fly at 50 yards. 2 1/2" at 50 yards for 25 - 30 bullets was spectacular. all i had was a hole in the target made by the 200gr. i didn't need hearing protection either, nor did the rifle get hot or even luke warm.
|
|
|
|
Post by Bullshop on Jul 30, 2023 10:50:16 GMT -7
A good hit with a lower powdered round is better than a mis or worse yet a bad hit with a magnum round.
|
|
|
|
Post by grasshopper on Jul 30, 2023 15:10:45 GMT -7
I don’t have any hand loading experience to share with this crowd but I do have a good bit of experience shooting 30 and 22 cal subsonic ammo. The military(Army anyway) when I was in had settled on mostly a 150gr semi pointed boatail bullet for subsonic duties when using rifles in 308. For the 22 cal applications they used both 55 and 93 grain semipointed bullets that had to my eye more of a flat base, if you can imagine it looked like a upside down cheerleaders megaphone but with just a tad more point. If I were to compare them to common commercial bullets most in this forum are familiar with imagine a Remington 150gr “power point” in 30 cal and size it down to 22 cal. I hope that’s not too confusing, sometimes what makes sense in my mind does not always translate into others being able to visualize it as well. I also remember that for the 30 cal subsonic loads ranges were kept to about 150 yds and 22 cal were kept inside 100yds. I got to observe the use of both 45 and 9mm subsonic ammo but I have no actual experience shooting it so I will reserve comment on these and they may not apply here anyway since we are talking about rifle calibers and loads here. Probably not a lot of useful info here, just what I remember us shooting when we were starting to use suppressors and subsonic ammo throughout the military where in the past these had been reserved for use by the top tier special operations forces of each branch. I’m sure the military has since only refined and improved what they use now.
|
|
|
|
Post by Bullshop on Jul 30, 2023 16:55:53 GMT -7
That is interesting Rob ! I didn't know that suppressed subs were in general use by the services. As for the 93 grain 22 bullets I think that bullet weight choice was a direct spinoff from Larry Kelly's developmental work with the whisper cartridges. That and the fast rifling twist rate for the long bullets he tested. That is likely why the 300 BO has a 1/7" twist rate as standard.
I think he used very low drag bullet designs thinking that they should work best regardless of the velocity weather super or subsonic. I will credit two sources for the development of bullet nose shapes that are most efficient for subsonic velocities. One is the US Navy for their work with torpedo nose shape related to cavitation at subsonic speeds and the other source that likely deserves the most credit is black powder cartridge competition. There has been more effort put into nose shape design for subsonic velocity by that group than any other. Considering that those fellows are self funded as opposed to federally funded its pretty amazing that the private sector got it right and the fed sector copies them.
|
|
|
|
Post by grasshopper on Jul 30, 2023 20:06:25 GMT -7
Hey Pard! When I started my hitch in the Army only the top tier 1 units were using suppressed weapons. Things really started to change after 9/11. The mission for a lot of units changed drastically. Most of the Army’s divisions were set up to fight some sort of conventional war much like what happened during the first Gulf War. The Army saw this really wasn’t the type of enemy it would be facing in the new back then Global War on Terror. They started to concentrate on special operations forces and had the larger regular Army units start training on small unit tactics. That all being said, when this happened they also started to train many more snipers and they went back and really started to teach basic and advanced marksmanship. This helped tremendously, to the point each unit would have several designated marksman. When this happened you really started to see the use of suppressors army wide. Since I retired quite a few years ago now I’m not sure how or how much that might have changed and since both Iraq and Afghanistan are no longer fields of battle I would doubt they are being used by anyone other than special operations today. Another reason they are probably not in use army wide is the army has gotten much much smaller and today the services are having a hard time meeting the recruiting numbers. I know I typed a lot of words but don’t think I’ve really said all that much, the bottom line is suppressors are much more common in the military then they were back in the mid to late 80s when I first started. I also think it’s great that civilians played such an important part in the research and design of bullets meant to stay subsonic!
|
|
|
|
Post by Bullshop on Jul 30, 2023 21:17:23 GMT -7
I had to laugh a little about the term, "" designated marksman"" The reason I laughed is because before the turn of the 19th century the same term was being used in the US military. I have an 1884 Springfield rifle that I believe was one of the few designated marksman rifles issued to the troops that through their demonstrated marksmanship ability were given that distinction and issued special rifles that had also proven superior in accuracy. I have the Book of the Springfield and in it the author mentions that there were such rifles that were non standard in some way. He said in this book that he planned another book specifically about the marksman's rifle but so far as I know no such book has been published. The rifle I have has the standard Buffington rear sight which is a great target sight but a poor battle sight but its front sight is the only one of its king that I have ever seen that appears to be original to the rifle. The rifle has the standard pinned in blade front sight but over that is a hooded sight with cross hair that perfectly aligns with the standard front post. Its a unique sight that I believe to be the special marksman's issued sight. So far I cant find any definite information on this sight accept for the mention of it in the Springfield book. It would be nice to know for sure but even if not the rifle is a superb shooter and the special sight makes it more shooter friendly for long range precision shooting.
Something else I wanted to mention about the Springfield rifle with the Buffington sight. They long ago understood all the issues involved with long range precision shooting they just had to do the math by hand. The Buffington sight with slider is calibrated to 2500 yards on the sight scale. The interesting thing is that the sight staff is not vertical to the level rifle but it cants several degrees left so the farther the sight is extended the farther left is the aperture. The reason for the leftward cant of the sight is to compensate for bullet spin drift from right hand twist rifling. Yup they knew about such things as spin drift and Coriolis effect even then.
You want to read some interesting stuff about the development of the 45-70 cartridge read about the Sandy Hook trials where they tested the cartridge out to two miles. I found it fascinating about the development of the right bullet length and shape combined with a specific twist rate to keep the bullets center axis in line with the trajectory so that at two miles bullets would land nose first and not belly first maintaining the axis center at the launch angle which for two miles would be a very steep upward angle. Also that at two miles the bullets landing nose first still penetrated 9" of packed beach sand so even at that range you wouldn't want to be catching those. This kind of ballistic stuff simply intrigues me.
|
|
|
|
Post by grasshopper on Jul 30, 2023 23:31:14 GMT -7
Again just wow! I never knew that the military had used that term in the past and probably would of never guessed it was that early. Just goes to show like we talk about often here the “old timers” knew much more than most people would ever believe. The sight on your trapdoor sounds really interesting, I know it takes time and it’s not your favorite but do you think you might get the boss to take a picture of that sight and post it here? I can’t be the only one that would love to see the sight you describe! Thank you again for sharing some of your vast knowledge about all things firearms related! I mean that and I’m not trying to be funny at all, every time I read a post you wrote I always take away something I didn’t know before!
|
|
|
|
Post by shootist---Gary on Jul 31, 2023 12:25:32 GMT -7
Daniel, when I found the article on my computer about the Sandy Hook trials, I copied it, & put the papers in with my other "Trapdoor" reference material. I have re read it a couple times, & told guys at gun shows about the Buffington Sight. Most of them did not know about why it adjusted to the left. I have been re reading Elmer Keith's book, "SIXGUNS" since i found it last week, packed away with other books, in a tote tub in my garage. When I called Tina to tell her I had found it, did I understand her, that you already have a copy? Let me know, as if you don't, I'll send you mine after I finish reading it. I bought this book back in the 1970's if I remember correctly.
|
|
|
|
Post by Bullshop on Jul 31, 2023 15:10:14 GMT -7
Hey - *GrassHopper* --- here ya go |
|
|
|
Post by Bullshop on Jul 31, 2023 15:10:28 GMT -7
and a couple more Attachments:
|
|
|
|
Post by Bullshop on Jul 31, 2023 16:06:11 GMT -7
There are five things about this rifle that lead me to believe that it may be one of the rarest of all trapdoors the marksman's rifle. Those features are first the front sight that so far is the only one I have ever seen. The Confederate Enfield sniper rifle used a very similar sight so may have been copied by them Yankee devils.
The second is the forged piston grip that was or so I had thought limited to the officer models and seems to afford a much more secure hold on the wrist of the stock by supporting the rear of the hand.
Third is the initials carved in the stock that some previous owner has tried to hide with some type of filler. Since the marksman's rifles were issued to very specific troops it stands to reason that this rifle would belong to one person so not stacked with rifles for regular troops. These rifles all had a stacking swivel mounted with the front sling swivel. The stacking swivels had an open bottom that could be hooked into the stacking swivel of other rifles and these were hooked together with several rifles and stacked into tee-pee like stacks in army encampments. This rifle has the front sling swivel but lacks the stacking swivel a fourth indicator.
The fifth indicator is the rifles accuracy. The marksman's rifles just as the marksman that used them had shown superior performance and so were chosen for this special duty. I have numerous times fired 1 moa groups at 100 yards with this rifle. It can also on a good day when the available light allows a good focus in the aperture of the Buffington sight match the accuracy of my best Sharps rifles with much better quality target sights.
The real issue with the Buffington sight is not that it is not a precision sight but that it is barrel mounted putting it much farther from the eye that a tang mounted sight and so being much more difficult to focus through that tiny hole. Fortunately they also saw fit to put a V-notch that corresponded with each upper and lower aperture so that when light was poor there was a second and fast choice.
|
|
|
|
Post by missionary on Jul 31, 2023 16:07:06 GMT -7
That bayonet ramrod is another story all by itself.
That front sight looks alot like the "cross hair" front sight made for the .58 Zouave musket. Dixie used to sell them very cheap and some where in all our stored goods.
|
|
|
|
Post by grasshopper on Jul 31, 2023 16:53:47 GMT -7
Thank you so much for posting those pictures!! Just when you think you have seen it all something new and wonderful comes along. The front sight reminds me of the type used on early aircraft during WWI. The sight is very interesting but I thought the attached pice under the wrist was even more interesting, can you give us a bit of history on this unique feature? I’ve seen a bunch of trapdoors and own an 1884 model but I have never seen that sight and likewise never seen the addition to the wrist/grip. Thanks again for posting those pics! Can you tell us the story of how you acquired this rifle and where it was discovered? Thanks pard!!
|
|
|
|
Post by Bullshop on Aug 1, 2023 7:06:57 GMT -7
I acquired this rifle at a gun show in Butte Montana. It seemed like to the rest of the patrons there as well as the seller it was just another trapdoor but it stood out to me. The book I mentioned also had just a mention of the attached pistol grip stating they were most common to the officers models. It also said there were two types the type I have shown and one made of wood. It said the original metal type were forged metal where as replica versions are castings and by that description this one appears original.
Because of its uniqueness I paid the highest price I have ever paid for a trapdoor for this one at $700.00 but I have no remorse over that I am quite happy with it. It seems that every time I take it out shooting is a pleasurable experience and reaffirmation of money well spent.
I added the picture of the Buffington rear sight so you can see the built in cant to the left that is to compensate for spin drift from right hand twist rifling.
|
|
|
|
Post by grasshopper on Aug 1, 2023 9:02:53 GMT -7
Thank you my friend! I figured it was something like that, as far as how you found it. Seems like for you and me the guns others will pass by just seem to cry out “over here” and we have go and closely inspect it and then it’s all over except for opening up the wallet! It’s an interesting piece to be sure I suppose they used iron on the first model because that’s what they had to use and thought it would be tough enough to withstand the weather and the Yankee soldier! I’m sure you have some records on this rifle since you’ve had it but have you recorded the best long range group you have shot? (Bet you have)😁
|
|
|
|
Post by Bullshop on Aug 1, 2023 17:34:14 GMT -7
You bet I have Bud ! So far the longest range I have fired this rifle is to 600 yards and at that range and in good light I do as well with it as any of my black powder cartridge rifles all having much more user friendly sights. That in a nut shell is the short fall of the trapdoor the barrel mounted sights. When you put a good tang sight on a good trapdoor they will shoot nearly as good as the much more refined target rifles. One other thing about the trapdoor is the three groove 20" twist rifling. The trapdoor is superbly suited to the 500 grain round nose arsenal bullet but if you try to kick up the BC with longer heavier bullets everything falls apart. An original three groove in very good condition can shoot quite well but it has been pretty much proven that a 5 groove with more narrow lands and grooves will shoot better. None the less a good marksman can do some powerful good shooting with a trapdoor in good condition.
I would have to go look up a " best load" recorded for the rifle but without looking I can tell you that the bulk of the load is black powder. The smokeless kicker does not make it shoot any better it just allows for longer strings of fire before cleaning becomes necessary to maintain accuracy.
I will add an amusing story about my adopted Dad. When he was a young man in his 20's he bought a surplus trapdoor and case of surplus ammo for $5.00 After the state (MT) relocated a few grizzlies from Yellowstone to the Bitterroot where he lived and those bears started causing damage to livestock the state hired a few local boys to hunt and dispatch them. There were five bears and of those my Dad got three. The most interesting one as he told it was one day while sleeping in the saddle his horse was approaching a water troth. Just as he arrived at the troth one of the bears that had been sleeping out of sight of his approach on the far side of the troth stood up and caused his horse to buck him off. He had been riding with his Springfield across his lap and when he got bucked off the horse the gun fired and killed the bear. Call it what you will half luck and maybe half awake reaction but it got the job done. That right there is a testimonial to the effectiveness of the 45-70 TD with original BP arsenal ammo. In my lifetime I have read a pile of books and articles about the 45-70 and right from its beginning to the present I have read it described using nearly the same words as being "" a dependable killer of big game "" and with that I absolutely concur.
|
|
|
|
Post by shootist---Gary on Aug 1, 2023 18:23:59 GMT -7
Daniel, my 1884 Trapdoor is also accurate with the 535 gr. Postell bullets that you cast for me, on the 805 yd "buffalo" at Forsyth when I do my part with judging the wind. I'm fine with elevation, using the "peep hole" on the Buffington sight set a bit above 800 yds. I am shooting 68 gr. of 1 1/2 Swiss powder. I was shooting 70 gr. with the 500 gr. arsenal bullets that you cast for me, but cut back 2 gr. for the 535 gr. bullet. Also, I weigh all of my powder charges on a digital scale, drop tube 30", then compress the powder, add a 10 thousands veggie wad, a newspaper disc, then the bullet, compressed to just engage the rifling for length. I also do pretty well on the 405 yd. target.
|
|
|
|
Post by Bullshop on Aug 2, 2023 6:33:25 GMT -7
Well Gary you know that is because my bullets have magic at no extra charge. For me in more than one 20" twist 45 caliber barrel the longer Postell bullet has not done as well as the shorter gov. bullet. The Postell bullet has worked well for me in 18" twist barrels. Sounds like you have your load well refined. I just loaded all my 40-90 brass yesterday with its preferred refined load. So far its best load is with a .7cc kicker of LT-30 and 79 grain by weight of Schuetzen FG powder dropped but not compressed with a .060" circle fly wad seated to the powder in unsized cases. The bullet is seated by hand then the cartridge run into the FL sizing die just enough to add enough friction so the bullets wont fall out but still can be pulled out with fingers. The bullet is our custom Postell that drops from the mold at 1.31" length is bumped to 1.295". It is left at the .410" diameter that it drops from the mold at and lubed with our NASA lube. This so far has been the most accurate 100 yard load. Yesterday I made a paper target using a wood pallet covered with large carboard boxes then that covered with white butcher paper with a sheet of black construction paper for a bull. The purpose of that target is so that I can measure groups that I plan to fire at 100 yard intervals from 200 to 1000 yards. That should be quite an interesting project that should provide a lot of useful information. I believe I will wait for the weather to cool down some because out where I most often shoot long range the tallest thing for shade is sage about knee high and it has been hot for us in the low 80's. Yea I know but that is hot for us.
|
|
|
|
Post by grasshopper on Aug 2, 2023 10:28:14 GMT -7
Woohoo!! Man! Now that my friend is a bear story you just don’t hear everyday!!(well unless you happen to be one of Dan’s kids that is) Yoo know I love ya pard! Just gotta keep you on your toes! I loved that story even though I did have to admit I was more than a little envious of your dad. I’m sure cowboys and ranchers or just anyone trying to survive the big sky in those days just thought of it as a chore to be done. Things were so much more efficient in those days! You got some men that wanted a hand at problem solving and went at it. Nowadays you would have to form a committee, vote on it, etc etc, you get my point. What a deal too! $5 was never spent so well!!
|
|
