.375 Winchester in Marlin 375

[madtrapper143]

Just aquired a Marlin Model 375 in, of course, .375 Winchester from a fellow Gunnutz member. I had visions of building a load for this rifle to bring out it's full potential. I have Hornady 220 gr flat points and some Re 7 powder. Here lies the problem, when I load the suggested amount of powder the bullet seats and then the compressed powder pushes the bullet forward. This load is a compressed one for sure. I want a load that will move the 220 bullet at 2200 fps with re 7. Any recipes or suggestions? I am not comfortable with a load that has to be compressed that much. (it is safe and the data is from a reliable source) What I am looking for is a load that moves the 220 the same speed as the winchester factory 200. (2200fps) Stated fps with the compressed load is over 2300 . Any help would be appreciated. By the way I shot a 5 point buck with the factory fodder last week and it really knocks them compared to my .30-30 or .303 Savage.

cheers Darryl

 

[agilent_one]

My only suggestion would be to give H4198 a try. 34 grains is listed as max.

 

[Little Howie]

I use 32 grains of H4198 with the 220 grain Hornady bullet. Unfortunately I have not checked this with a Chronometer but it groups better than factory loads in my Winchester Big Bore (seems to leave the bore dirtier, though)

 

[Lee Enfield]

Try a 6" "drop tube" (ala black powder) to fill the case more efficiently.

D

 

[senior]

What you ask may be very hard to do. I worked with that same gun for many years & never got that kind of velocities

Factory 200s do run at 2200fps but factory 250s only gave 1750-1800fps
I believe once you go over 200gns the velocities drop of very fast with heavier bullets. The best velocity I ever got with 220gn Horns was 2100fps w/36gns of H-4198 & I believe that was TOO hot a load
I was never able to get the published results with RL-22.

Here's my best for you to try
Best hunting load 33.5gns of IMR4198 gave me 2" groups @ about 1950fps

The best accuracy was 32.5gns of IMR4198 for some 1" results

I found H-4198 to be a good powder giving consistant 100fps more velocity but in my gun it just would never show the accuracy that the IMR powders did

Pretty much all loads in the 375 are compressed loads you just have to use a little crimp & pick a load your happy with. Another hint that may help a little is not to trime your brass to minimum length, it may not be much diff between min & max but max is the length of a crimp which will help in this caliber.