SOLD/EXPIRED 375 Allen Magnum repeater....

[casspir]

Kirby,

I suspect that the new 500 cal would be purely academical. As I said I used to have a 500 A-Square and a 460 Wby, 458 lott and a watt. Now back then I had a lot more muscle than today and I am bigger than the normal person. The recoil was not managable. I never could shoot it accurately out of hand and I sold the rifle/s. I never could achieve more then 2350fps with a 500gr Barnes bullet. Tested it at the SA Police Forensic lab with all the powders available and suitable to that cal but nope the proclaimed speed by Art Alpin in SA was not achieved. Gladly so, the recoil was astronomical.

Seen so many buffs killed by a more accurate bullet (even .223) than a big magnum.

There are however always a place for a new cal.lightbulb

I do like the 338 AM and 375 AM. Longrange shooting cal in high wind drift makes sence. I am not familiar with hunting in the US. Planning to hunt there in 2011.

That is if I can get past your Visa control. They are extremely difficult and rude. Cant blame them. So many idiots want to hi jack your country.

 

[LR3]

Thanks Casspir, I ll be in Botys and E Tvl.

You ll enjoy a 338 or 375 on a Chey Tac case. Great combo.

 

[Fiftydriver]

LR3

If we started right now it would be so close I could not garantee it. I have been working my rear off to get my shipping times cut down. At the first of the year they were right around 26 months shipping time from order. Currently, after this batch of rifles, I will be around 16 months. By the end of the year, my goal is around 10-12 months. That will be about the shortest I could do with the time it takes to get alot of these rifle parts in shop to build on but working hard to get to that point but as I said, it is probably around 5-6 months out if things keep going as they currently are.

 

[Fiftydriver]

Casspir,

The design goal of the 50 AT and the 458 AT for that matter was never as a "Stopper" rifle but for an option for a heavy tactical rifle in the class of the 50 BMG but in a much lighter rifle.

Something that offered legit +1000 yard reach, more kenetic energy then the 408 CT but in a comparible weight rifle.

The rifle design was to be around 18-19 lbs. Lehigh makes a solid high BC bullet for the 458 caliber and at the time I designed my 458 AT reamer, Wildcat Bullets was going to order bullet making dies for a 600 to 700 gr HPBT lead core bullet in .458" caliber with a BC in the .800 to .850 range.

The 50 AT was designed around the 750 gr A-Max and it can drive this bullet to within 100 fps of what the standard 50 BMG can drive this bullet to using conventional 50 BMG chamber pressures.

All that said, if loaded to more moderate levels, either could be chambered in a rifle such as the CZ magnum receiver that will accept the 505 Gibbs and use conventional big game bullets.

Yes, recoil would be far more then pleasant!!! I tested the 50 AT in a 16 lb rifle with poor muzzle brake for the rifle design and recoil was brutal. With the new muzzle brakes I have now in the Painkiller line, I suspect it would be much more pleasant to shoot but have yet to test that theory trying to get caught up with shipping times.

 

[LR3]

Thanks Kirby for your response. I appreciate how busy you are and that s why I was so pleased to be able to get your 375 repeater without the wait that you had warned me would take some 18 months. I ve started loading for it and look forward to practicing popping some paper with pills in the near future before elk season.

As far as a .458, I ll hold on that for my Africa trip next year but I go back nearly every year so I ll check on your waiting list for it down the road.

Keep up the great job and producing the works of art we are privileged to use.

LR3

 

[casspir]

Yipp Kirby, I completey missed the boat here, my apologies. For that purpose I suspect it would be great.

 

[LMK]

Kirby,

Do you have a case capacity for the .375 AM in grains of water? I think the stock .375 CT is 151 and was curious how much volume you picked up in your improvement.

Alternatively, what would the capacity be for Retumbo when loaded to the base of the projectile? I assume you have more capacity than required to reach a max load of Retumbo?

Thanks

 

[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]

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.