35 Whelen twist

[historicfirearms]

IF one were having an M1 rebarreled to 35 Whelen, what twist rate is ideal for cast boolits? The rifle would be used for deer, elk, and bear hunting.

Schuff's mini G in 35 Whelen sure looks like fun.
http://shuffsparkerizing.com/services/the-mini-g/

[Love Life]

Wow. That would be some serious punch!! $925 for the whole kit and caboodle (Conversion plus 35 Whelen barrel) doesn't seem bad at all!

[Larry Gibson]

14" twist would be my choice. Would handle cast bullets of 250 gr very well (jacketed too) to just bout as fast as you'd want to push them in the M1.

Larry Gibson

[Shuz]

If you are gonna use real heavy boolits like the Lyman 358009 @ a nominal 280g, I'd advise you go with a 1:12 twist.

[Le Loup Solitaire]

I shoot Lyman 358009 in a rebarreled 1917 that was done with a 1 in 12 twist and it shoots very well. LLS

[Larry Gibson]

Folks might note this is for a M1 conversion so over all cartridge length and gas port pressure come into play. The M1 rifle limits both thus the heavier cast seated to crimp groove may not fit the magazine and the heavier weight bullets with many powders will give too high gas port pressure with many medium or slower burning powders for optimum performance.

Larry Gibson

[JesterGrin_1]

Larry there Gas System is Adjustable so it will enable one to use a wide variety of Cartridge Pressures and Function well.

So the main things to worry about is rate of twist and overall cartridge length. As for Rate of Twist I would also say 1-14 but I can not comment on Overall Cartridge Length needed.

[Larry Gibson]

Yes the there are a couple different adjustable gas plugs for the M1. However they are designed for use with 175 - 180 gr bullet and maximum charges of 4064/Varget powder in the '06. I have seen several M1s damaged with too much gas port pressure even with the adjustable plug in use. I had it explained by an engineer well versed in gas pressure that the adjustable gas port does not alter the "impingement velocity" of the gas as it enters the gas cylinder. The higher the gas port pressure the higher the velocity of the gas as it enters the gas cylinder. Also the higher the gas port pressure the higher the residual pressure in the chamber and the case may still be expanded gripping the chamber wall when the oprod tries to open the bolt. If the gas port pressure and the cycling of the bolt are not timed properly with the contraction of the case then the system begins to beat itself up with damage occurring sooner or later. Seen that happen too many times on 1000 yard matches where some were trying to get the last ounce of oomph out of the '06 cartridge.

Those adjustable plugs are not designed for 280+ gr bullet over doses of slower burning powders. Those may easily give gas port pressures that are too high with top end loads for the M1s operating system even with the adjustable gas plugs. Hard to say as it's all conjecture at this point on our part but I wouldn't spend $900+ for the conversion just to mess it up for the sake of using the heaviest cast bullet available. Is the OP really going to hunt anything with an M1 in 35 Whelen that a 250 gr cast at 2400+ fps won't kill? The Whelen made its bones on that bullet weight at that velocity. With the 14" twist the option is also available for the 200 or 180 gr bullets (cast or jacketed) to be pushed to 2600+ fps with accuracy, if the system will take it. That will a lot harder to do with the 12" twist.

Larry Gibson

[historicfirearms]

Larry, you are truly a wealth of information. Thank you for all the help you have unknowingly given me over the years.

250 grain boolits will be plenty for all I plan on doing, so 1:14 twist it will be.

[Larry Gibson]

That should do well and thanks for the comments.

Larry Gibson