|
Joined: Jan 2008
Posts: 2,066
Campfire Regular
|
Campfire Regular
Joined: Jan 2008
Posts: 2,066 |
I couldn't get within 3 grains of loads with the 160 grainers that other guys were running. It's okay though half moa and 3180 from a 150 swift scirroco isn't too bad at all. I'm good on everything up to elk with that combo.
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
79: No doubt that will work... Not sure i ever asked but what is your OAL of loaded cases?
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Jan 2008
Posts: 2,066
Campfire Regular
|
Campfire Regular
Joined: Jan 2008
Posts: 2,066 |
I haven't played with a loaded round in a while but I think that I was loading them to like 3.57. My rifle Is throated for a 175 partition to 3.565 if I recall. I'm still off the lands with the 150s but that's where I found the accuracy.
Last edited by 79inpa; 02/19/16.
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
You're long enough, that's for sure. Mmm....guess it's the barrel. Really not sure.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Feb 2001
Posts: 8,772 Likes: 6
Campfire Outfitter
|
Campfire Outfitter
Joined: Feb 2001
Posts: 8,772 Likes: 6 |
What are the options for 7 Mashburn dies? Is RCBS the only game in town and what do they get for a set? I missed a set on ebay that went for $33 because I wasn't there to bid :-(.
Does anyone rent this reamer and if not, is there a smith with one that would long chamber a barrel that I would finish? I'd prefer to do everything myself but the parts for this caliber are not generally available. Buying a new one is an option as well. Redding had 7mm MSM dies...the S bushing dies...sitting on the shelf when I call them. It took several months to get them because Redding was so far behind in there shipping schedule. Not sure what its like now. The 7mm MSM reamer my smith has is one of his very first.From 20 some years ago.Think it was one of the very first rifles he ever built. dave
Only accurate rifles are interesting.
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
79: I'm sure you know all this,but barrels vary all over the map. Some are tight, some are loose,some are rough and some are smooth. They have different numbers of lands,different throat lengths,different materials. Even how the lands are configured can affect how the bullet engages the lands and affect velocity. All these variables can conspire together to increase or decrease resistance that the bullet encounters in traveling down the bore. Mix in different powder lots, bearing surface of different bullets,materials used,etc and it's no small wonder we see differences in the velocity from the same cartridge and bullet, and same load,from one rifle to another.And why we can even run into the pressure walls without getting the velocity we expect of a cartridge. If we hand load enough, we have all bumped into this stuff at one time or another. The one variable that seems to overcome all the others IMHO is case capacity,and even then we get into issues of pressures that we mostly all just take educated guesses at reading. But the point is that even though we don't alway get everything we want from a cartridge, we will generally get more than with any case that's smaller and holds less powder. One chap (buddy) I know who had a Mashburn said that his 168 gr Barnes did not get the 3200 fps others seemed to be getting with 160 gr bullets.Velocities were barely over 3100 fps. I speculated that was because it only weighed 7 gr less than a 175 gr Partition,and maybe had even more bearing surface. I never worked with the Barnes in the Mashburn but for yuks sometime, measure a 160 Partition.....it ain't .284.(or at least it was not the last time I measured one)...Hint.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Apr 2011
Posts: 15,354 Likes: 10
Campfire Ranger
|
Campfire Ranger
Joined: Apr 2011
Posts: 15,354 Likes: 10 |
That's pretty good stuff and your right, 3180 with that Swift is really a killer load. I actually like the expanded Swifts a little more than the ABs but both are really capable bullets.
I've tried 33 with the 175's and I'm still not sold they are gaining me anything over a load of H1000 running 50fps slower. My only need right now is getting a single jug of H1000 so I'm working with the same lot of powder. When I started with the MSM I had to buy 1lb'ers from where I could get them so a great load out of one jug turned mediocre from the next.
I've got another buddy that picked up a Simillion rechambered M70 off of here. He has yet to shoot it, but plans on running 7828 which seems like it should be just as good as H1000 or maybe better. I had plans of trying a bunch of stuff with mine but once I ran H1000 I sorta lost interest since it worked so well.
Semper Fi
|
|
|
|
Joined: Feb 2001
Posts: 8,772 Likes: 6
Campfire Outfitter
|
Campfire Outfitter
Joined: Feb 2001
Posts: 8,772 Likes: 6 |
Chanlynn barrel is 26 inches and has a 1-10 twist.
The load is a 168g Berger classic hunting bullet with a Norma case and a Tula mag primer.Powder is H1000.
Measured 10 feel from the end of the barrel with my Oehler model 33 with a 10 foot spacing.4 shot groups except where noted..No errors on the chrono at all this session..
72g 3 shot L.. 2970 H.. 3051 ES.. 81 A.. 3013 SD.. 40
73.5g L.. 3035 H.. 3041 ES.. 16 A.. 3032 SD.. 6
74.5g L.. 3083 H.. 3125 ES.. 42 A.. 3099 SD.. 18
75.5g L.. 3118 H.. 3137 ES.. 19 A.. 3126 SD.. 8
76.5g L.. 3162 H.. 3186 ES.. 24 A.. 3171 SD.. 11
77.5g 3 shots L.. 3215 H.. 3231 ES.. 16 A.. 3221 SD.. 8
The 77.5g load has one case of the 3 fired,that has a very, very faint hint,of an ejector mark.Hard to actually tell The other two look fine.I knocked the primers out of all 3 and reprimed them.The one with the ej mark was just a little bit less effort to seat a primer with a RCBS hand priming tool.Than the other two.All 3 function through the action like butter with no tightness. Im thinking a person could actually run the 77.5g load but just looking....im afraid they would open the primer pockets over time. Ashame as the 77.5g load shot the second best accuracy at 400 yards.
The 73.5g load at 400 and the 73g load at 100 were the best for accuracy.
The 73.5g load shot an honest 3 inch 4 shot group at 400 yards. Say 3032 fps with a SD of 6.
The hotter loads were all running MOA or a bit more at 400. Conditions were kinda suckie.Wind was up pretty good.Still shot great..
dave
Only accurate rifles are interesting.
|
|
|
|
Joined: Jun 2002
Posts: 9,921
Campfire Outfitter
|
Campfire Outfitter
Joined: Jun 2002
Posts: 9,921 |
I couldn't get within 3 grains of loads with the 160 grainers that other guys were running. It's okay though half moa and 3180 from a 150 swift scirroco isn't too bad at all. I'm good on everything up to elk with that combo. What powder charge with those 150s? I'm using the same bullet in my 7 WSM and am getting 3100+.
|
|
|
|
Joined: Jan 2008
Posts: 2,066
Campfire Regular
|
Campfire Regular
Joined: Jan 2008
Posts: 2,066 |
I'm at 69.5 grains of mrp with the 150 grainers. beartalker
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
bearstalker the people I know who are using 150's in the Mashburn are generally getting 3250 fps,or a bit more(not quite 3300) or about 100 fps more than 79 is getting with his rifle.
I got that velocity with 150's in the 7mm Dakota and the cartridges are very similar in velocity.
What mine will do with 150's I can't say as I have never fed it anything lighter than 160, unless I was fire forming.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Jan 2005
Posts: 22,884
Campfire Ranger
|
Campfire Ranger
Joined: Jan 2005
Posts: 22,884 |
Im thinking a person could actually run the 77.5g load but just looking....im afraid they would open the primer pockets over time. You could load one case 10x in a row and fire it off, you'll soon see if/when the primer pockets will open. If you get to 10x and it is still holding primers satisfactorily, I would consider that load in that brass safe to go.
|
|
|
|
Joined: Feb 2001
Posts: 8,772 Likes: 6
Campfire Outfitter
|
Campfire Outfitter
Joined: Feb 2001
Posts: 8,772 Likes: 6 |
If I see a hint of an ejector mark. Im done. If its as hot as I think it is, you would not get to 10 reloads. And I do, do that ...ie firing the same case over and over again, to check the primer pocket.
dave
Only accurate rifles are interesting.
|
|
|
|
Joined: Dec 2007
Posts: 1,523
Campfire Regular
|
Campfire Regular
Joined: Dec 2007
Posts: 1,523 |
Well I've got a 7 Mashburn FL die now and it looks like I'll be able to use my Hornady seater so once I get a reamer, I'll be in the game. I sized one piece of once fired Hornady 300mag brass and had significant puckering and cracks in the shoulder. I didn't anneal and will try that, but it looks like I might want to make up a intermediate form die. Does anyone have any pics of the brass as they come out of the form die(s)? I'd like to get an idea of how the shape progresses.
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
gzig: Don't use once fired cases to form your Mashburn brass.Start with new brass. On the left is a new 300 WM case that has been passed through a Form/Trim die before being fire formed. A Pass through a FL Mashburn die should result in the same thing and no case wrinkles/buckling. The next two cases are live fired 7mm Mashburn Super,fully formed. There is not much progression, other than a bit less taper for the Mashburn case.
Last edited by BobinNH; 02/28/16.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Dec 2007
Posts: 1,523
Campfire Regular
|
Campfire Regular
Joined: Dec 2007
Posts: 1,523 |
Thanks for the pic Bob. I don't have any virgin brass at the moment but I did anneal a couple R-P cases and they came out OK. I'll get some new brass to start with when the time comes. Do you or any others have a favorite brand? Any that form better or are more uniform than the others?
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
gzig: I only use WW. Others I know use Norma and Hornady as well.
Those using Norma have had a donut issue but resolved it quickly. I have not run into it with WW. Hornady is fine too.
Honestly they all work.
Annealing helps with any of them. Will prolong case life.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Apr 2007
Posts: 3,723
Campfire Tracker
|
Campfire Tracker
Joined: Apr 2007
Posts: 3,723 |
Tried to run a new piece of brass through my FL dies and it didn't quite form it enough to get it to chamber. Guess Im going to have to invest in a forming die since the 100 pieces I formed with Dobers dies have just over 700 rounds on them so they are almost on their last leg.
|
|
|
|
Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
|
OP
Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
Laker: Are you camming over with the FL die? Set it up to contact the top of the shell holder with the ram fully up. Then, turn the die down another 1/2 turn (maybe a bit more). Run the case in and until you feel contact and then lean on the handle and you will feel it "bump" down further. They should chamber fine. It had been a couple of years recently since I had to make any new brass, and I forgot to do this myself. Got to the range with a bunch of COW loads and nothing chambered. I knew right away what I had done, so took them home and cammed them all over. They now fit fine.
Last edited by BobinNH; 02/29/16.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
|
|
|
|
Joined: Apr 2007
Posts: 3,723
Campfire Tracker
|
Campfire Tracker
Joined: Apr 2007
Posts: 3,723 |
I tried that Bob but it still wasn't quite enough. I may have to play with it some more. I still may end up buying the die anyways. Wife has basically taken my mashburn now anyways so I might be building myself another one this spring
|
|
|
|
575 members (12344mag, 10gaugemag, 160user, 06hunter59, 16gage, 19rabbit52, 63 invisible),
2,802
guests, and
1,255
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
Forums81
Topics1,193,644
Posts18,512,428
Members74,010
|
Most Online11,491 Jul 7th, 2023
|
|
|
|