8mm-280ackley

fnuser · Posted: Mon Dec 22, 2008 9:57 pm Post subject: 8mm-280ackley

Just built a pretty nice sporter on a 1909 argentine, My second job is at a gun repair shop working front counter taking jobs in, answering questions etc. am a hobby gunsmith w\ some talent looking for anyone that has experience w\ 8-06 ackley, 320 Howell, 3200 hawk, etc I fireformed some norma .280 REM w 60g of h380 and Remington 185's no pressure sign but cases are well formed. I've read alot of loads for 8-06 and 30-06 ackley and have clculated 105% of 8-06's just looking for some real world experience. Anyone try h380 or imr 4064? it looks like you can compress imr 4064 and imr 4350. i have alot of .323 180 ballistics (300) Called a.h.r. and the guy on the phone said they hadn't sold any 320's is someone trying to tell me something?

fnuser · Posted: Mon Dec 29, 2008 6:54 pm Post subject: Re: 8mm-280ackley

worked up some loads for aa-4350 and h380 61.7 g for both came up to bottom of neck. shot over a chronograph they both were clocking @2950 with the nosler 180 bt's the h380 were feeling like max loads as the bolt was hard to lift. I don't think I'll use that load as is, might try it w\ a 170 g bullet though. The aa-4350 seemed just about right. but is probably as high as I'll go. The results were about what I expected but it would have been nice to break 3000 w a 180. Maybe a slower powder would work? I have alot of rl22 around as I use it alot in .270's. I was amazed at the difference between the 60g, h380, 2650 fps fireforming load and the 61.7g,h380, 2950 fps hot one. Makes me scratch and think. that means I must be on the borderline for danger if the velocity increased that much w\ only a 1.7 g increase. I may make some more 60 g h380's in brass that has been fire formed. Would the unformed brass "cushion" the pressure enough to make the difference? Some non-ballistic observations were I rattled my redfield model 70 peep loose will re-assemble w\ blue locktite. all screws were loose including the itty bitty ones holding the knobs on. and the two big ones holding the base to the rear bridge. The recoil in a 7 pound gun was o.k. after testing, I loaned it to 4 other people that work in the same shop I do and have fired 30-06's alot they thought it was about the same. the rifle was fired 50 times today over 3 hr's of fooling around. Barrel is a montana riflesmith length is 24" and is a slim european taper w\ barrel band and banded n.e.c.g. front sight groups from the sitting were .75" at 50 yds.

fnuser · Posted: Wed Dec 31, 2008 12:51 pm Post subject: Re: 8mm-280ackley

check gallery for pics of fnuser's rifle. He built it himself and he's not proud at all.

fireball 3 · Posted: Wed Dec 31, 2008 8:47 pm Post subject: Re: 8mm-280ackley

FN-nice rifle.. Have you built any 8mm wildcats besides a 8-06? I built a 8mm/300win mag..! Dave

I use IMR 4064 ,REM brass, REM 9 1/2M primers and Speer 200gr spitzers and have had excellent results...

fnuser · Posted: Thu Jan 01, 2009 2:58 pm Post subject: Re: 8mm-280ackley

I may be splitting hairs but it's a 8-280 Ackley and after all splitting hairs is kinda what it is about, right. I have developed loads for some other 8mm's. The 8x56 Mannlicher-Schoenauer had alot of heavy bullet loads but I worked some up for lighter bullets that are handier for deer I have a mod1908 ms chambered for that in a carbine that is a neat little package complete w trapdoor buttplate and folding receiver sight. are you needing data for your 8-300win? I would compare case capacity w 8x68. and adjust accordingly. I have dies for the standard and reamer for the Ackley improved version. Still might build one, But am waiting to find a deal on an express length action. My wife gave me a standard length f.n. action for Christmas. and I have several barrels laying around one is a tapered octagon in.264 groove, 1-9 twist. I was thinking I might do a .256 newton. I have a short magazine f.n. action also. What technique do you use to ream your chambers? I don't get to compare notes very often so I'm curious. It sounds like you use Remington components any input as to why or is that what is available. I'm not against using any brand that works, again just curious, and the internet seems like a good tool to satisfy curiousity. Have you tried any slower powders? It seems to me thet with a case to bore ratio larger than a 8mm gibbs it would start to be an advantage. Have you had the opportunity to chronograph any of your loads. I'm finding that a case full of powder volumetrically seems to offer the same velocity albeit at different pressures. I would think your 4064 load would be less than compressed or numerically <100%. Most of the loads that work at their maximum effect per g. of powder are @93-95 density. Thats what I was tryng to find. So far though, I am stuck at 100% w aa 4350{max velocity w 180g bullets and acceptable pressures.}

fnuser · Posted: Mon Jan 12, 2009 5:30 pm Post subject: Re: 8mm-280ackley

My second posting listed a fireforming load at 60g of H380 I cannot duplicate this data. And believe some error on my part is to blame. I do know that the velocity and charge weight were correct which only leaves powder type. I have recorded velocity since w 60g of H380 and the 180g nosler ballistics it is a lot faster than the 2650 f.p.s. listed prior to this. So I believe the pressure to be about right w\ the norma brass. which seems to be thicker also the case head seams to be softer so it grips the bolt face a little more than others also, causing bolt lifts to be sticky when the 61 g+ charge is approached. I still think this would be a better powder w a slightly lighter bullet say 170-175. This is on my list of things to try w this caliber, also nearly every reloading manual I come across lists a imr 4064load, also on my list I was just hoping a ball powder would give the results I wanted anyone ever try BL-C2?