Musings with a model 1907 Win 351 wsl
Mar 15, 2024 18:14:31 GMT -7
todddoyka and shootist---Gary like this
Post by Bullshop on Mar 15, 2024 18:14:31 GMT -7
Because of the scarcity and high price for 351 WSL ammo I started looking to possibly add it to our inventory of obsolete cartridges. Because of the fact that usable brass can be made from 223 Rem and the astronomical price of factory ammo the potential profit margin to produce 351 ammo made from 223 seems attractive. With that in mind as well as making 300 BO and 221 FB I ordered 1000 rounds of cleaned 223 range brass for $40.00.
A friend of one of our boys had us hunt for a model 1907 Win in 351 wsl because he wanted one for sentimental reasons. We finally found him one and ordered it for him. He lived over the divide so wouldn't get over to pick it up for awhile so I secured permission to use it to develop some loads.
I picked up a mold on ebay made for Buffalo Arms for a copy of the original 180 grain round nose gas checked bullet designed for the 351. I already had a vintage Lyman mold for their 350447 a 190 grain flat nose gas checked bullet . I had always believed that the Lyman 350447 was for the 348 Win but found it interesting that when used in the 351 and crimped into the crimp groove on that bullet over all cartridge length is exactly right for the model 1907 clip. They feed well and shoot quite accurately. I had expected possible accuracy improvement with the flat nose over the round nose because it has substantially greater bearing length. It did shoot better than anything tried up to that point but I am getting ahead of myself.
Because it was a borrowed rifle I didnt really have the time to work up good accurate loads only loads that functioned but with acceptable accuracy lacking. Because of not being satisfied with the accuracy I was getting and because I ran into a good deal on a 1907 I decided to get the rifle and spend more time trying to develop accurate loads.
I watched every video on youtube about the 351 in the model 1907 and the one thing missing from all videos was targets. There is lots of information about making brass and loads but in all the videos I watched only one showed the target. He didnt say at what range he was shooting but it looked to be about maybe 25 yards and the group looked to be about 5". That seemed about normal for what can be expected and maybe my first try with the borrowed rifle was a wee bit better but not much.
Now that I have had time to work with my own rifle and not be rushed I have learned a few things about the 351 in the model 1907 Win. One thing I had been wondering about a possible cause for poor accuracy was head space. The original 351 used a rimed case so head space was positive. Using the rimless 223 I wondered if perhaps we were introducing the potential for variable primer ignition since the rimless case could fall too far into the chamber and be dependent on case length for head space instead of rim thickness.
On my initial batch of brass I trimmed them to suggested trim length at 1.376" In that I erred because after I expanded the case for the 35 cal bullets they shortened to 1.370" They were then too short but interestingly they all fire without problems.
What I found was that the extractor even though designed for a rimmed case still gets a firm hold on the rimless case so must limit the depth at which the cartridge can enter the chamber. That must be the reason there were no misfires but still I suspect some variation in primer ignition.
On the next batch of brass formed I decided to expand the cases before the final trim at 1.382" I left the cases .002" longer than suggested max length because to improve powder ignition I am applying a heavy crimp which in effect shortens the case length for head spacing purpose. I thought if I could get the case mouth right up to the chambers end and with the extractor holding the case back perhaps it would improve primer ignition.
Now when it cam to powder selection what I found once again was that I was on my own. The most recommended powder for the 351 is IMR 4227. First trying that even with the starting loads bullets were stripping and shooting perfect profiles at 25 yards. There must be a vast difference in internal case volume between original 351 brass and reformed 223 brass. Now that I have some experience under my belt I can say without question that if using reformed 223 brass powder burn rate faster than Win 680 # 132 on the burn rate chart is too fast. Powders between Win 680 and Accurate Powders #2200 are about perfect loading to 100% density and giving top achievable velocity for the cartridge at normal chamber pressures. Powders slightly slower burning than 2200 may be acceptable as to burn rate but the density is off. This case is going to be limited to ball powders because other types can not get enough powder weight in the case to still be able to seat the bullet and stay within normal safe pressures. The powder choices are limited but three that I have found to be about perfect are Win -680, Accurate-2200 and Accurate LT-30. With these three you can get enough weight in the case to get top velocity about 1900 fps at normal safe pressures and not compress the powder.
With faster powders chamber pressures seem to spike quickly and can not reach top velocity for the cartridge. This is quite noticeable when sizing fired cases going from normal pressures and sizing with one hand on the press handle to going to too high a pressure and needing two hands on the press handle to FL size cases. All my loads with the slower powders are smooth sizing with one hand.
Since the model 1907 Win is a straight blow back action lacking a locking bolt it has a pretty heavy recoil spring so the pressure window for smooth functioning is very narrow between not enough pressure to cycle and too much pressure (two hand sizing).
Oh yea and another thing I changed is bullet diameter . Where I initially started using .351" I have now gone to .352". I would like to try even larger but that is the diameter both my molds drop at. I have an idea to try some 38/357 bullets sized to the next largest diameter sizer die I have at .355" That will be for future exploration but really not needed with the level of accuracy these mentioned refinements have produced which is about 1.5" 50 yard groups and 3" 100 yard groups which is quite an improvement from my first efforts with the 351 wsl in the model 1907 Win.If anyone is interested in my best loads to date using commercial 223 reformed cases,
1
BA 180gn RNGC @ .352" BHN-22
cci 400 primer
17gn Accurate 2200
2
Lyman # 350447 @ .352" 190gn BHN-22
cci 400 primer
16gn Win 680
3
BA 180gn RNGC @ .352" # BHN-22
cci 400 primer
16.7gn WW 680
4
BA 180gn RNGC @ .352" BHN-22
cci 400 primer
Accurate LT-30
My favorite of those is #2
A friend of one of our boys had us hunt for a model 1907 Win in 351 wsl because he wanted one for sentimental reasons. We finally found him one and ordered it for him. He lived over the divide so wouldn't get over to pick it up for awhile so I secured permission to use it to develop some loads.
I picked up a mold on ebay made for Buffalo Arms for a copy of the original 180 grain round nose gas checked bullet designed for the 351. I already had a vintage Lyman mold for their 350447 a 190 grain flat nose gas checked bullet . I had always believed that the Lyman 350447 was for the 348 Win but found it interesting that when used in the 351 and crimped into the crimp groove on that bullet over all cartridge length is exactly right for the model 1907 clip. They feed well and shoot quite accurately. I had expected possible accuracy improvement with the flat nose over the round nose because it has substantially greater bearing length. It did shoot better than anything tried up to that point but I am getting ahead of myself.
Because it was a borrowed rifle I didnt really have the time to work up good accurate loads only loads that functioned but with acceptable accuracy lacking. Because of not being satisfied with the accuracy I was getting and because I ran into a good deal on a 1907 I decided to get the rifle and spend more time trying to develop accurate loads.
I watched every video on youtube about the 351 in the model 1907 and the one thing missing from all videos was targets. There is lots of information about making brass and loads but in all the videos I watched only one showed the target. He didnt say at what range he was shooting but it looked to be about maybe 25 yards and the group looked to be about 5". That seemed about normal for what can be expected and maybe my first try with the borrowed rifle was a wee bit better but not much.
Now that I have had time to work with my own rifle and not be rushed I have learned a few things about the 351 in the model 1907 Win. One thing I had been wondering about a possible cause for poor accuracy was head space. The original 351 used a rimed case so head space was positive. Using the rimless 223 I wondered if perhaps we were introducing the potential for variable primer ignition since the rimless case could fall too far into the chamber and be dependent on case length for head space instead of rim thickness.
On my initial batch of brass I trimmed them to suggested trim length at 1.376" In that I erred because after I expanded the case for the 35 cal bullets they shortened to 1.370" They were then too short but interestingly they all fire without problems.
What I found was that the extractor even though designed for a rimmed case still gets a firm hold on the rimless case so must limit the depth at which the cartridge can enter the chamber. That must be the reason there were no misfires but still I suspect some variation in primer ignition.
On the next batch of brass formed I decided to expand the cases before the final trim at 1.382" I left the cases .002" longer than suggested max length because to improve powder ignition I am applying a heavy crimp which in effect shortens the case length for head spacing purpose. I thought if I could get the case mouth right up to the chambers end and with the extractor holding the case back perhaps it would improve primer ignition.
Now when it cam to powder selection what I found once again was that I was on my own. The most recommended powder for the 351 is IMR 4227. First trying that even with the starting loads bullets were stripping and shooting perfect profiles at 25 yards. There must be a vast difference in internal case volume between original 351 brass and reformed 223 brass. Now that I have some experience under my belt I can say without question that if using reformed 223 brass powder burn rate faster than Win 680 # 132 on the burn rate chart is too fast. Powders between Win 680 and Accurate Powders #2200 are about perfect loading to 100% density and giving top achievable velocity for the cartridge at normal chamber pressures. Powders slightly slower burning than 2200 may be acceptable as to burn rate but the density is off. This case is going to be limited to ball powders because other types can not get enough powder weight in the case to still be able to seat the bullet and stay within normal safe pressures. The powder choices are limited but three that I have found to be about perfect are Win -680, Accurate-2200 and Accurate LT-30. With these three you can get enough weight in the case to get top velocity about 1900 fps at normal safe pressures and not compress the powder.
With faster powders chamber pressures seem to spike quickly and can not reach top velocity for the cartridge. This is quite noticeable when sizing fired cases going from normal pressures and sizing with one hand on the press handle to going to too high a pressure and needing two hands on the press handle to FL size cases. All my loads with the slower powders are smooth sizing with one hand.
Since the model 1907 Win is a straight blow back action lacking a locking bolt it has a pretty heavy recoil spring so the pressure window for smooth functioning is very narrow between not enough pressure to cycle and too much pressure (two hand sizing).
Oh yea and another thing I changed is bullet diameter . Where I initially started using .351" I have now gone to .352". I would like to try even larger but that is the diameter both my molds drop at. I have an idea to try some 38/357 bullets sized to the next largest diameter sizer die I have at .355" That will be for future exploration but really not needed with the level of accuracy these mentioned refinements have produced which is about 1.5" 50 yard groups and 3" 100 yard groups which is quite an improvement from my first efforts with the 351 wsl in the model 1907 Win.If anyone is interested in my best loads to date using commercial 223 reformed cases,
1
BA 180gn RNGC @ .352" BHN-22
cci 400 primer
17gn Accurate 2200
2
Lyman # 350447 @ .352" 190gn BHN-22
cci 400 primer
16gn Win 680
3
BA 180gn RNGC @ .352" # BHN-22
cci 400 primer
16.7gn WW 680
4
BA 180gn RNGC @ .352" BHN-22
cci 400 primer
Accurate LT-30
My favorite of those is #2
