375 Allen Magnum repeater....

[Fiftydriver]

It depends on what brass is used but on average its around 12% larger in capacity then the standard 375 CT.

My standard load is 144.0 gr Retumbo which was good for right around 3300 fps in a 33" barrel length. This is greatly dependant on what lot of powder used as powder charge can range from 142.0 gr to 146.0 gr depending on lot of powder.

With the 350 gr SMK, load density with Retumbo is surpisingly high. Into the low 90% range so it works very well.

[LMK]

Kirby,

I appreciate the info. We spoke some time ago and I was unable to wait for one of your guns so I designed my own reamers for a .375 CT Improved and Dave Kiff made them for me.

I don't know if you remember but I sent you a copy of my reamer print and you graciously gave me some good tips to help me along.

So far so good, I have about 30 rounds through the gun breaking it in. My last loads I worked my way up to 139 gr or Retumbo with no signs of pressure, and plan to continue to increase my charge to approximately the same loads you have developed.

The case will hold a little under 160 gr. of Retumbo when filled to the base of the bullet so I will also be in the the 90+% range on density @ 145 gr. Have to admit I got a little lucky there, I was just pushing the the 35 degree shoulder as far forward as I could and took out taper based on your advice. No sticking cases after 3 firings so I have to thank you for that as well.

I appreciate your guidance and can't thank you enough for what you are doing for the sport and novices like me. Thanks again.

Lonny M Kirk

[dariuszczyszczon]

Originally Posted by Fiftydriver

It depends on what brass is used but on average its around 12% larger in capacity then the standard 375 CT.

My standard load is 144.0 gr Retumbo which was good for right around 3300 fps in a 33" barrel length. This is greatly dependant on what lot of powder used as powder charge can range from 142.0 gr to 146.0 gr depending on lot of powder.

With the 350 gr SMK, load density with Retumbo is surpisingly high. Into the low 90% range so it works very well.

I Read and your tread and have question of different lots? Does fps change considerable of different lot of powder if you are only using 65 gr? (I have loads done for a 7 rem mag).

[Fiftydriver]

Dariuszczyszczon,

It really does not matter what size of a powder charge your using, lot to lot variations can be significant with all powders and in all chamberings. Anytime you start a new lot of powder, its always good to record the velocity of your old load, then drop your powder charge with the new lot of powder 5% and work up again over the chrono.

In most cases, you can still get back to the same exact velocity but it may take a different powder charge to get to that point, sometimes it may be less, sometimes more and sometimes right on the money but its always good to start low.

Actually, the smaller the case capacity, the more siginficant burn rate variations can effect pressures and velocity. Always best to start low and work up again if nothing else just so that you know that your velocities are the same as your old load.

[Fiftydriver]

LMK,

I hope your projects works out great for you, I suspect it will, sounds like its performing as it should already.

Habe fun and good luck, if you have any more questions feel free to ask and if I have any meaningful experience I will offer all my data freely.