.277 Caliber Experiences


Active Member
Aug 13, 2001
Logan, UT
Anybody have experience with either the Sierra MK 135 or the Lost River J-36 135 in .277 caliber?

The Lost River has a BC of .649, and it seems I could easily achieve 3200 FPS with the bullet. Sounds like great LR material. Any input appreciated.

Yes, the 135 MK 270 bullet does well. I have friends who hunt with them in their light weight carry in Sendaro rifles chambered in the 270 Cal.

You are about maxed out at 1000 yards with them if you try to stay above 900 to 1000 Foot pounds of energy. That's why most Longrange hunters like the heavier weight and higher BC bullets so they can reach out even further and with more energy.

If you have a 270 with a longer barrel to increase the velocity, the 135 MK or the Jenson bullet would work quite well. Check with Warren as per the twist and land configuration you may need in your barrel.

Hey Wapi-T

Your barkin right up my ally. I've been using the 135MK on whitetail for the past few years and for the first time at longrange this past season. It has yet to show me any reason not to use it.

As for the J36, well I just started load developement back in january. First results were pretty damned discouraging but I haven't given up hope yet. I'll have to do a little tweekin with seating depths and powder charges, but a 3" 200yds group was not what I was expecting. But then again I believe that it was Warren who told me that his bullets were more likely to preform best in factory barrels (tad on the lose side) vs a custom barrel (a little undersized). Well I got to go so I'll talk at ya later.

I have heard that the J-36 fouls barrels like crazy. Your experience?

Also, do you get better velocities out of the MK or the J-36? Thanks.
Actually the j36 didn't seem to foul any more than the other bullets. As for velocities, I didn't have time to set up, but suspect that I was getting slightly lower than the 135MK. Point of impact was approximatly the same. The load that I was working on that day has since clocked a just below 3800fps. That seems to be right around the most accurate spot for the MK. In colder weather I had pushed it up further but think that I will keep it between 3750 and 3800, no need in pushing it further.

Thanks for the information

I knew it had to be a large case to get that much velocity.

I thought maybe Wapti (The original poster) had picked up on that much velocity also because he mentioned a 277 caliber.
One would tend to think of a 270 Winchester cartridge. i believe I mentioned the 270 in my first post also.
NO 270 Winchester is capable of that much velocity even if it used a 100 gr bullet let alone the 135 MK.

I have a question or two.
How many rounds do you have through the barrel to date?
I once had a 30/378 Weatherby with a 37" barrel that gave me 3600 FPS with a 200 Gr MK. That one killed many deer and elk out to 1360 Yards with no problem at all.
I can imagine the flight time at 3800 with that 135 gr out to say 500 or even 1000 yards---Don't blink your eye or you will miss the hit.

I also have a friend who had a 270/300 Win Mag and somehow got a simalar 7mm bullet (he swears it came from the factory that way) bullet in the 270 bullet box. Being only .007" larger he mistakenly (not paying attention) seated it into his case and fired it.
The Remington action held but, you should see it. They had to cut the barrel out of the action to get the bolt out and you should have seen the bolt face and the steel that was missing from it. He was VERY lucky.
Be carefull.
I still don't know how he could have missed the added neck tention when seating the 7mm bullet but, he did.

Thanks again.

[ 04-01-2002: Message edited by: Darryl Cassel ]
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