270 allen express

[douglasbeasley]

What are the top loads being used in the 270 allen express (powder type and weight)?

[Fiftydriver]

Your not going to get much information because there are not many out there!!! [img]/ubbthreads/images/graemlins/grin.gif[/img]

Powders for this round will be Rl-25, H-1000 and Retumbo as well as the slow ball powders such as Ramshot magnum, AA8700 and US869. WC872 is pretty slow for this case capacity which is very similiar to a 7mm STW in capacity. These would be for bullets in the 140 to 169.5 gr range.

For the lighter bullets, Rl-22 and H-4831 can also be used with good results. Just have to watch your pressures because you can pressure out in this case capacity with these powders.

Powder capacities depending on what bullet weights you use will be in the 78 to 90 grain range depending on what powders you use. The lower end will be for the faster stick powders, for heavier end for the very slow ball powders.

These are averages. Some barrels will be a bit more, some a bit less.

Kirby Allen(50)

[Ridge Runner]

my stw responds very well to a charge of 872, during testing 94 gr of 872 sent a 160 nosler downrange at 3340 fps, was surprising since its only a 26" tube.
RR

[Fiftydriver]

It will work but I like to get working pressures up a bit higher with WC872 so it burns as clean as possible. Did you get much powder fouling with that load, I suspect a bit!

Just a bit on the slow side to keep pressures up there in the 65,000 psi range that is best to get WC872 to burn as clean as possible is all.

Certainly it will work well at lower pressures, just have to keep a watch on carbon fouling.

Kirby Allen(50)

[DontKickDontKill]

Speaking of WC872, just how temp sensitive is it? I was thinking about getting a 7mm Ultra Mag, and thought about this powder with the heavier bullets.

[Fiftydriver]

It would be amazing in the 7mm RUM with heavier bullets, +175 gr would be best in my opinion but it will also work well in the 160 gr class.

It is a ball powder and as such it is sensitive to temp changes. Some do not like this but I feel the positive characteristics of this powder outway these issues.

If you want to load to full tilt pressures, have a summer and winter load, or if your like me, just load a few grains under max and be happy with that.

It is however sensitive to temp changes but no more so then any other ball powder from what I have seen.

Kirby Allen(50)

[Ridge Runner]

It did in fact score me a bit when it first came to me that it was temp sensative, but further testing has shown me how it can be regulated.
I cut my powder charge 4 grains in my 7mm Allen to shoot above 75 degrees, and still shoot the same velocity, quick multiple shots will give you a heavy bolt lift in warmer temps, here's the results of my tests
7mm Allen mag all velocity's are with 160 gr accubonds and 105 gr of WC872 in a 9 twist 4 groove lilja 30" long
single didgets to 55 degrees 3470-3495 fps
55 to 75 3520-3550 fps
75-95 3650-3720 fps heavy to impossible bolt lift
JS