270 Allen Mag

10 October 2007, 14:47

Dr B

270 Allen Mag

I'm considering a 270 Allen Mag for long range work. Does anyone have any experince with this round or with any of the other Allen Mags.
For thoes not flamilur with the allen mags they are developed by gunsmith Kirby Allen. the 270 AM is the 7mm RUM necked to .277

Here is Kirbys description

270 Allen Magnum

7mm or 300 RUM - parent case

Ballistics: 169.5 gr. ULD RBBT @ 3450 fps in 30" barrel; 195 gr. ULD RBBT @ 3200 fps in 30" barrel. This is by far the most popular and easiest to load of the entire Allen Magnum and Allen Xpress line of cartridges. Simply run a 7mm RUM or 300 RUM through a 270 AM FL die to neck down, load and shoot and out comes a formed 270 AM case ready to be trimmed and loaded with full tilt loads. No case neck annealing is needed with this round especially if you use 7mm RUM cases.

This is a very high performance round that will dramatically surpass any factory offered magnum round with the use of the two listed bullets above. The 169.5 gr. is recommended for long range deer hunting and the heavy 195 gr. ULD RBBT is for heavier game such as elk. Any powders suitable for the 7mm RUM round will work equally as well in the 270 AM. You can also use bullets such as the 130 gr. Ballistic Tip and
140 gr. Accubond loaded to 3800 and 3625 fps, respectively. For 600 yard and under deer hunting, these are about as flat shooting as you can get. At longer ranges, the heavier bullets have better ballistic performance and penetration on big game.

This round has accounted for many head of game taken over 600 yards and in the first spring of testing, it harvested 5 rockchucks at ranges from 990 yard to 1250 yards all with one shot kills in a heavy sporter-weight rifle. It also holds my personal best 500 yard three shot group at 0.543" center-to-center for three shots at 500 yards. It is a very accurate round and extremely easy to load for.

10 October 2007, 16:45

jeffeosso

not for nothing, but the .284 bullets have better and more choices for the heavy bullets.. which also have a high BC.

why did i say that? You wanted it for long rang work, and the 7rum is a factory deal... and if you need a longer tube, "anyone' can do the rebarrel

btw, reducing the bullet diameter, no other changes, results in LESS vel for same SD bullet at the same pressure...

in other words, *I* wouldn't go wild cat here, i would have shilen make a match barrel and chamber it with a througher for the longer bullets
jeffe

10 October 2007, 20:25

ramrod340

I've always opted for the 7mm over the 270 bullets. I have also played more with the 7mms.

10 October 2007, 21:01

pdhntr1

Dr. B,

Kirby is on longrangehunting.com forum. You may want to become a member and research some of the information there if you haven't already.

Allen mag shooters is just one of many threads that may help.

Jim

11 October 2007, 16:05

philny1

quote:
Originally posted by Dr B:
I'm considering a 270 Allen Mag for long range work. Does anyone have any experince with this round or with any of the other Allen Mags.
For thoes not flamilur with the allen mags they are developed by gunsmith Kirby Allen. the 270 AM is the 7mm RUM necked to .277

Here is Kirbys description

270 Allen Magnum

7mm or 300 RUM - parent case

Ballistics: 169.5 gr. ULD RBBT @ 3450 fps in 30" barrel; 195 gr. ULD RBBT @ 3200 fps in 30" barrel. This is by far the most popular and easiest to load of the entire Allen Magnum and Allen Xpress line of cartridges. Simply run a 7mm RUM or 300 RUM through a 270 AM FL die to neck down, load and shoot and out comes a formed 270 AM case ready to be trimmed and loaded with full tilt loads. No case neck annealing is needed with this round especially if you use 7mm RUM cases.

This is a very high performance round that will dramatically surpass any factory offered magnum round with the use of the two listed bullets above. The 169.5 gr. is recommended for long range deer hunting and the heavy 195 gr. ULD RBBT is for heavier game such as elk. Any powders suitable for the 7mm RUM round will work equally as well in the 270 AM. You can also use bullets such as the 130 gr. Ballistic Tip and
140 gr. Accubond loaded to 3800 and 3625 fps, respectively. For 600 yard and under deer hunting, these are about as flat shooting as you can get. At longer ranges, the heavier bullets have better ballistic performance and penetration on big game.

This round has accounted for many head of game taken over 600 yards and in the first spring of testing, it harvested 5 rockchucks at ranges from 990 yard to 1250 yards all with one shot kills in a heavy sporter-weight rifle. It also holds my personal best 500 yard three shot group at 0.543" center-to-center for three shots at 500 yards. It is a very accurate round and extremely easy to load for.

If you should decide ya can't live without one (as I did at one time) and don't wanna wait. I have one I'm thinking about parting with.

270 AM
Rem 700 action
30" fluted Lilja barrel plus brake.
H-S Precision stock
Jewell trigger
Wyatt mag ext.
169.5 gr ULD RBBT bullets, around 100
Dies

Around 400 rds down the tube.
Doesn't like the 195s.

13 October 2007, 21:44

Ridge Runner

I thought the 257,6.5, and 270 Allen's were based on the 338 Rum case?
Oh well, I have a 7mm Allen, its the most accurate rifle I have ever shot, I've never been much for shooting groups but with me runnin the trigger my rifle has shot 1 7/8's" at 660 yds.
I think you'd be better off with the 7mm due to the fact that better brass is available and you can get reasonably high BC bullets in .284 dia. without going custom
Right now I'm shooting a 160 nosler accubond at 3500 fps with 110 gr of WC872 mil-surp, which is 4 bucks a pound, an awesome deer load to 1000 yds.
If the .277 bullet diameter is what ya gotta have look into the 277 Allen Mag, it uses a 338 LM case and you can't buy better brass.
RR

14 October 2007, 00:51

Dr B

quote:
I thought the 257,6.5, and 270 Allen's were based on the 338 Rum case?

These are the specs I got from Kirby Allen. I would like to use a Rem 700 action and their is contraversy about opening up a 700 to 338 Laupa head dia..
DR B

Allen Mags

224 Allen Magnum...........270 WSM
257 Allen Xpress...........300 Dakota
6.5mm Allen Xpress.........300 Dakota
270 Allen Xpress...........300 Dakota
257 Allen Magnum...........338 RUM
6.5mm Allen Magnum.........338 RUM
270 Allen Magnum...........7mm or 300 RUM
277 Allen Magnum...........338 Lapua
7mm Allen Magnum...........338 Lapua
300 Allen Xpress...........338 Lapua *
300 Allen Magnum...........408 Chey Tac *
338 Allen Magnum...........408 Chey Tac
375 Allen Magnum...........408 Chey Tac *
458 Allen Magnum...........408 Chey Tac *
50 Allen Tactical.........408 Chey Tac
510 Allen Magnum...........50 BMG

14 October 2007, 04:30

philny1

quote:
Originally posted by Ridge Runner:
I thought the 257,6.5, and 270 Allen's were based on the 338 Rum case?
Oh well, I have a 7mm Allen, its the most accurate rifle I have ever shot, I've never been much for shooting groups but with me runnin the trigger my rifle has shot 1 7/8's" at 660 yds.
I think you'd be better off with the 7mm due to the fact that better brass is available and you can get reasonably high BC bullets in .284 dia. without going custom
Right now I'm shooting a 160 nosler accubond at 3500 fps with 110 gr of WC872 mil-surp, which is 4 bucks a pound, an awesome deer load to 1000 yds.
If the .277 bullet diameter is what ya gotta have look into the 277 Allen Mag, it uses a 338 LM case and you can't buy better brass.
RR

WC872--hope ya have a supply, understand its sudddenly become hard to come by.

14 October 2007, 06:29

Ridge Runner

its been replaced by WC868, just a tad faster, I have 14# of 872, when its gone I'll find something else

Kirby will open up a blued action to 338 but not SS
RR

14 October 2007, 22:52

dempsey

I love my .270wins, but a .270 as a base for a long range rig would be my last choice. It just makes little sense compared to larger calibers for so many reasons.

15 October 2007, 00:31

philny1

quote:
Originally posted by dempsey:
I love my .270wins, but a .270 as a base for a long range rig would be my last choice. It just makes little sense compared to larger calibers for so many reasons.

Have an interest in hearing your reasons.
A 195 gr ULD RBBT at 3200 fps doesn't sound to shabby to me. Don't know what the BC is, would guess .800 or better. Mild recoil, can spot your own hits--still find it interesting.

15 October 2007, 01:51

dempsey

quote:
A 195 gr ULD RBBT at 3200 fps doesn't sound to shabby to me

Sounds great, but their are several bullets that sound great in larger calibers that have a longer history for the application and hence many more components. Pretty much as simple as that.

15 October 2007, 02:58

.366torque

quote:
Originally posted by Dr B:
quote:
I thought the 257,6.5, and 270 Allen's were based on the 338 Rum case?

These are the specs I got from Kirby Allen. I would like to use a Rem 700 action and their is contraversy about opening up a 700 to 338 Laupa head dia..
DR B

Allen Mags

224 Allen Magnum...........270 WSM
257 Allen Xpress...........300 Dakota
6.5mm Allen Xpress.........300 Dakota
270 Allen Xpress...........300 Dakota
257 Allen Magnum...........338 RUM
6.5mm Allen Magnum.........338 RUM
270 Allen Magnum...........7mm or 300 RUM
277 Allen Magnum...........338 Lapua
7mm Allen Magnum...........338 Lapua
300 Allen Xpress...........338 Lapua *
300 Allen Magnum...........408 Chey Tac *
338 Allen Magnum...........408 Chey Tac
375 Allen Magnum...........408 Chey Tac *
458 Allen Magnum...........408 Chey Tac *
50 Allen Tactical.........408 Chey Tac
510 Allen Magnum...........50 BMG

A few "plasma torches" in there!!

15 October 2007, 06:58

jeffeosso

so, basically, the bsae cases are
404 (wsm, dakota, rum)
416 rigby (lapua)
505 gibbs (cheytac)
or 50BMG

16 October 2007, 04:55

Dr B

quote:
dempsey
one of us
Posted 14 October 2007 21:52 Hide Post
I love my .270wins, but a .270 as a base for a long range rig would be my last choice. It just makes little sense compared to larger calibers for so many reasons.

Dempsy

You are correct their are other rounds that have longer range capability than the 270AM. Kirby allen has made kills at 2300yd with the 338AM. But several other factors come into play ie just how long are your long range shoots going to be. A poll on LRH board showed that 80% of the people had never made a Big Game kill over 600 yds. I'm considering the 270 AN as a 800 - 1000 yd gun. The second consideration is weight and recoil. A light weight 338AM is usually 16 lb or so , a heavey one like Kirby Allen uses at 2300 yd weighs 80 lb. I want a under 10 lb rifle that I can carry in the feild, and won't kick to much.

I have a good light weight 600 lb yd rifle in my .257 stw I just want one with a little more leggs.

DR B

16 October 2007, 06:13

Tyler Kemp

A muzzlebreak would almost be needed on a light 270 AM if you plan on shooting it much, that's alot of recoil. But I guess hunting you wouldn't feel it...

16 October 2007, 08:14

dempsey

Dr. B, understood. I'm sure it will fit your needs. I do think Kirby will make good money on rebarrels with those rounds

16 October 2007, 17:25

Ridge Runner

some 270 AM's have made almost 1K rounds before accuracy fades enough to effect hunting accuracy, thats alot of years worth of LR hunting. after load developement in my 7mm AM I shoot maybe 10-15 rounds a year to confirm zero and the few shot taken at game. for practice I have a smaller capacity chambered rifle that mirrors the trajectory of my 7mm AM to 800 yds.
Besides, whats 600 bucks when you have a rifle that you are 100% confidant in at that kind of range? I know bowhunters who upgrade every year at that kind of expense to kill a deer at 30 yards.
RR