280 Imp. for F-Class

[Dave L Kiff]

I have a few customers that like the 284 match with the .317 nk and .188 free bore and then there is a group that like the Shehane throat of .223 fb 1deg30. I have customers that send in dummy rounds and they are every length from .175 out to .228 . My rifle has a .188 and shoots great, Thanks Dave

 

[LRCampos]

.

Thank you very much Mr. Kiff.

I will send you an order soon for a .284 reamer.


LRCampos.

 

[PALarson]

280 AI works well, I have been shooting one for several years at 1,000. Got my Hi Master card at 1,000 with it. Very satisfied with the accuracy. I was using it in a 40X receiver and did not like having to mess with the round each time I attempted to load it,and behold if a primer puked and I needed to remove the loaded round I had to unsling, pull the bolt out, and remove the round. Got tired of that and put a new barrel on a Model 70 target action, shoots as well and no hassel with loading and unloading. The 40X now had a 6 XC barrel on it and works well at 600. It has a 1-7.5 twist and will try at 1,000 with the115 DTAC bullets. That will come in a later post.

Paul Larson

 

[spitfire_er]

Good to hear from everyone.

I'm going to try and get out this winter and shoot it some more, all this talk has gotten me wanting to shoot even in the cold ND winter.

I too am going to build a 6xc for the 600 yard game over the winter. Figure it will save me a couple dollars over the year to shoot (It never seems to works out that way). I will for sure be shooting my .280 this season though.

I also checked my freebore, looks like I am pretty short, 0.065" (if I measured correctly) for the 180 class bullets but I can always run the throater in there. It is just a standard .280 RCBS reamer though so it was not originally set up for the 180's.

 

[flatlander]

I've been shooting 284s for several years now, and though I'm pleased with the 284's accuracy & ability to handle the 175-180gr bullets, it's discouraging having the primer pockets getting loose so quickly if one gets just a bit too liberal with the powder charge. Just did a quick comparison on case capacity, using fired WW 284 & R-P 280 AI (40*) cases; weights are with ball powder to base of the case neck. 284 - 63.96grs/280 AI - 69.8grs. So it would appear that the 280 AI should be able to - at the very least - equal the 284's velocity with the heavies.

I've got a Krieger 31" hvy Palma 1:9tw 7mm blank in the shop, plus 200pcs of RWS 280 Rem brass, plus a 40* 280 AI reamer, and a die set. What've I got to lose? There's a nice BAT 3LL prone rifle in the safe (already have 6.5x55AI & 284 bbls for it) that's way under-utilized, so another bbl for it might be a good way to get more use out of it. Too bad there's so much difference in case body dia between the 280 & 284; otherwise I could simply re-chamber one of several 284 bbls I have for the 280 AI. If I'm not happy with the results out of the 280 AI chamber, at least I can set it back and make a 7mm-08 Imp out of it. None of this would be of that much importance, but everything's so crazy right now, I have no idea how long it'll take to get another 7mm blank from either Bartlein or Krieger.

 

[PALarson]

Good post Flatlander, I to did have a standard 208, and decided to do the same upgrade with a AI reamer. Came out well, it is shooting superb and I didn't have to crack out one of my Kreiger 7mm beauties. Good luck.
Paul Larson

 

[Steve Blair]

I've been shooting 284s for several years now, and though I'm pleased with the 284's accuracy & ability to handle the 175-180gr bullets, it's discouraging having the primer pockets getting loose so quickly if one gets just a bit too liberal with the powder charge. Just did a quick comparison on case capacity, using fired WW 284 & R-P 280 AI (40*) cases; weights are with ball powder to base of the case neck. 284 - 63.96grs/280 AI - 69.8grs. So it would appear that the 280 AI should be able to - at the very least - equal the 284's velocity with the heavies.

[br]
You imply that the .280 case will somehow handle over pressure loads better than the .284 case. My experience is that .308 cases lose their primer pockets pretty quickly when abused. It seems likely that .280 cases will, too. Isn't it just a better idea to not subject your cases to pressures for which they were not designed? There is nothing wrong with the standard .280 or the AI and either would likely do as you say. David Bailey's worked well for him last year. But, the same can be said of the .284 Win or Shehane. I've fired thousands of .284 Shehane rounds through several barrels and get pretty good velocity and case life. The performance on target has also been pretty good. I have seen shooters blow out .284 Win cases trying to achieve Shehane velocity levels for a largely illusory [SIZE=small]ballistic advantage[/SIZE][SIZE=small]. I shoot the Shehane variant because of a wider tuning window, not for the ~80 fps that it gives me.[/SIZE]

 

[PALarson]

Sleepygator hit the nail right on the head. Anytime we over pressure any cartridge we are looking for problems. As one I have blown up a rifle blowing out cases and found out the hard way when I lost a $ 650.00 stock. My strong suggestion is to carefully work up loads until pressure signs are identified and then back off a little, noting the ambient conditions, as we all know hot humid weather increases pressure so my recommendation is be safe, be careful.
Paul Larson

 

[flatlander]

On the contrary - most of the loads I've used in my 284s haven't shown any typical signs of pressure - no cratered or overly flat primers, and no ejector swipes on caseheads. That's why I've been somewhat disappointed with how many of those cases have wound up with loose primer pockets after a couple of firings.

Also, I have no intention of loading a 280 AI to excessive pressure, but based on my experience over several years with three different 284 bbls, I wouldn't be surprised to find that 280 AI cases would handle loads that produce the same pressures as the 284s without loosening the pockets. I believe the rebated rim case design is the culprit.

 

[Steve Blair]

Well, I'm typically getting 6 firings from my Shehane cases, excluding fire forming which is done in a dedicated barrel at slightly lower pressure. I retire them when I switch barrels, so I don't know how many loads they would tolerate. My loads with H4831 SC and 180 Hybrids are in the 2940-2950 range from 32". It is a full pressure load with that powder but not over pressure. I'll stick with the Shehane because it works for me. [br]
Good luck with your .280 AI. There is no particular reason why it won't do well. A standard .280 Remington has about the same case capacity as the Shehane. The AI is about 5-6 grains more. You may even be able to leverage the extra capacity to make good use of slightly slower powders like N165 or IMR 7828 SSC.

 

[flatlander]

Steve,
That was the point I was trying to make - with nearly 6grs more case capacity than the std 284, a 280 AI should be able to produce velocities at least equal to what I'm getting out of my 284s at slightly lower pressure. If I had access to an Oehler M43, I'd really like to use it to derive the pressures I'm getting with H4831 & RL17 in the 284, then compare those pressures while I'm working up loads for a 280 AI. That'd beat speculating on how much pressure it takes to loosen WW 284 primer pockets.

I've recently purchased a box of Lapua 6.5x284, and after cutting the donuts out of expanded necks, will be doing some chronographing with it. The Lapua brass averages about 5.5grs lighter than the WW brass; be interesting to see how velocities compare with the same charge weights in both brands of brass, and how the Lapua primer pockets stand up to the same loads I've been running in WW brass. I'm pushing HBN coated 180 Hybrids just over 2800fps with H4831 out of a 28" Bartlein 5R. Compared to reported velocities I routinely see posted here, that's not a hot load.

 

[PALarson]

Good posts, as a 280 AI fan, I have found that it will do isn't best with N165. I got this hint from a friend who has also been very successful with the 280 AI. Good luck
Paul Larson