gerry
Ammo Smith
- Mar 1, 2007
- 6,908
- 1,791
A ragged hole very quickly, very nice. Looks like that factory barrel is a good one and there will be no need for a rebarrel.
7mm Mashburn Super Magnum
- Thread starter SJB358
- Start date
I was thinking 76 might be too hot if you got ejector marks at 77grs. Usually 1.5-2grs below ejector marks is where case life improves greatly with standard brass. That is moving right along at 3200fps and the accuracy is nothing to sneeze at. I guess there isn't a need for a new tube anytime soon.
BTW my 7-300's were the same way with the amount of rounds it took to find a load it likes. I used 3 and 4gr less in RWS brass than most said to use for H-1000 and 180's in Winchester brass. The first gun shot under 3/8" for 3 shots the first time out and the second one shot the load from the first one under 1/4" for rounds 3,4, and 5 out of the gun. I think H-1000 in a 7-300wm or 7 Mashburn is like H-1000 in a 338 Edge, it fits like a glove. I'm sure you'd get 40-50fps more velocity with R-33 but not all guns shoot it as accurately or have as low of ES's and SD's. My 30-338 Norma Imp loves the stuff but it's a bit more overbore compared to a 7-300.
BTW my 7-300's were the same way with the amount of rounds it took to find a load it likes. I used 3 and 4gr less in RWS brass than most said to use for H-1000 and 180's in Winchester brass. The first gun shot under 3/8" for 3 shots the first time out and the second one shot the load from the first one under 1/4" for rounds 3,4, and 5 out of the gun. I think H-1000 in a 7-300wm or 7 Mashburn is like H-1000 in a 338 Edge, it fits like a glove. I'm sure you'd get 40-50fps more velocity with R-33 but not all guns shoot it as accurately or have as low of ES's and SD's. My 30-338 Norma Imp loves the stuff but it's a bit more overbore compared to a 7-300.
- Thread starter
- #123
Thanks fella's, there is really something about it that was a ton of fun.. Just enough extra space with the slightly larger case than the 7mm Rem Mag and the ability to run the bullets out of the main body.
I was thinking the same thing Nathan, I know there is more speed to be had with Retumbo or RL33, but I since this is a used barrel, I might try to minimize the amount of load work I throw on it. The good thing about the rechamber is any throat erosion that was there as a 7mm Rem Mag was started fresh with the Mashburn.
I do think I may order a barrel. The only thing I can't really take advantage of is the 175 ABLR's.. I say can't, but I believe I am a 1-9.5", so they would be marginal at best. I'd really like the same set up with a 1-8 or better.. That would be something with a 175 ABLR around 3050...
Kevin, my shots actually average 3210, but depending on the lighting and temp I'd imagine they are anywhere from 3190-3220.. Either way, I am happy with it..
I was thinking the same thing Nathan, I know there is more speed to be had with Retumbo or RL33, but I since this is a used barrel, I might try to minimize the amount of load work I throw on it. The good thing about the rechamber is any throat erosion that was there as a 7mm Rem Mag was started fresh with the Mashburn.
I do think I may order a barrel. The only thing I can't really take advantage of is the 175 ABLR's.. I say can't, but I believe I am a 1-9.5", so they would be marginal at best. I'd really like the same set up with a 1-8 or better.. That would be something with a 175 ABLR around 3050...
Kevin, my shots actually average 3210, but depending on the lighting and temp I'd imagine they are anywhere from 3190-3220.. Either way, I am happy with it..
nvbroncrider
Handloader
- Aug 20, 2011
- 3,085
- 4
Scotty you might be surprised they stabilized in my 1-9" @ 2860 they might in yours at 3050.
I'd shoot the 168 ABLR's and be tickled pink if they shot like the 160AB's. You sure as heck don't need an additional 7grs of bullet weight to kill stuff. I know the lighter 160-168gr bullets have shot better on average then the heavier bullets in the 7mm's I've built. Load up some 162 Amax's and go looking for some woodchucks in a few weeks. It's good practice too. :lol:
- Thread starter
- #126
Great points fellas. Not too worried about it right now. With the 160 AB shooting well, I'm pretty happy with it as a hunting gun.
I've got a box of 162 AMaxs as well ill load up and check for speeds and accuracy. It'll make a good summer time practice load.
I've got a box of 162 AMaxs as well ill load up and check for speeds and accuracy. It'll make a good summer time practice load.
Dang Scotty you're giving me an itch here!
This thing has some pretty serious cool factor... just enough extra space over 7RM for 7mm Weatherby numbers w/o all the extra pressure.
You guys are jackin me up; every time I figure I've finished my last build you call to my attention something 'new'!
This thing has some pretty serious cool factor... just enough extra space over 7RM for 7mm Weatherby numbers w/o all the extra pressure.
You guys are jackin me up; every time I figure I've finished my last build you call to my attention something 'new'!
elkeater2
Handloader
- Jan 5, 2009
- 761
- 85
Scotty, I'm late to the thread and the pics aren't showing for me! 
Nevertheless, following the story has been a good read. You're going to have to plan on pursuing bigger stuff than the critters that mosey across your back yard now. Maybe that's been part of the plan, anyway! Congrats on your success
EE2
Nevertheless, following the story has been a good read. You're going to have to plan on pursuing bigger stuff than the critters that mosey across your back yard now. Maybe that's been part of the plan, anyway! Congrats on your success EE2
- Oct 30, 2004
- 24,344
- 3,185
What happened to all the pictures?
truck driver
Ammo Smith
- Mar 11, 2013
- 7,342
- 924
Looks like photo bucket ate them.
- Thread starter
- #131
SJB358":1xktf0na said:
Congratulations!
Looks like you are getting excellent results and hit your numbers with no trouble. From all I have read and seen this seems to be typical Mashburn performance, that is what got me excited about the project when I started on it.
I got to looking at those 175 grain ABLRs that came in the other day and ordered an 8 twist barrel blank long enough to finish at around 27" I'm going to try the slow burners in it, I have Retumbo, RL25 and RL33 along with WC867.
- Thread starter
- #133
I hope so. I am anxious to get it up and running.
Have you tried 7828 in your Mashburn yet? It seems to be pretty commonly available and I have seen a lot of good reports on it in the Mashburn. I am in the same boat as you are with H1000, down to a couple of pounds. I'm hoping for good results with the WC867 as I have 16 pounds of it left over from a .300 Ultra project that didn't work out.
Have you tried 7828 in your Mashburn yet? It seems to be pretty commonly available and I have seen a lot of good reports on it in the Mashburn. I am in the same boat as you are with H1000, down to a couple of pounds. I'm hoping for good results with the WC867 as I have 16 pounds of it left over from a .300 Ultra project that didn't work out.
- Thread starter
- #135
I haven't tried anything but H1000 so far Bob. I did load some 175 PTs with Retumbo the other day. I'll get a chance to shoot them soon I think.
I think something slow like RL33 or N570 or anything similar might be really good with the 175's speed wise. I hit gold with H1000 and 160's so I'm hesitant to mess with those at all. I scored 4 lbs of H1000, so I've got enough to hunt with this Fall. Everything else will just be experimenting.
I do think Retumbo and the others might generate some free speed if the accuracy can be retained. Right now I'm just goofy how well this thing shoots.
I think something slow like RL33 or N570 or anything similar might be really good with the 175's speed wise. I hit gold with H1000 and 160's so I'm hesitant to mess with those at all. I scored 4 lbs of H1000, so I've got enough to hunt with this Fall. Everything else will just be experimenting.
I do think Retumbo and the others might generate some free speed if the accuracy can be retained. Right now I'm just goofy how well this thing shoots.
- Thread starter
- #138
- Thread starter
- #140
