Home Forums Hunting & Shooting Ask The Gunwriters Question for MuleDeer on 7x57 throat dimensions!

John we have chatted before about 7x57s. I am thinking on a barrel for one of my guns and am considering the throat dimensions. I know from experience that the long throats of old are not the answer to my needs. What dimensions to you think would be good for 140-160 gr. hunting bullets. Nosler Partitions in particular. the gun I have now I load 160s to an OAL of 3.2" and its working good enuff. But it is finicky with anything lighter then 160s because of the length of the throat. The 140 gr. partition seems to have to float in space for a while before engaging the rifling. I know you had stated something about your Kilmanjaroo rifle having a lot more usable throat dimension for all around use.
Any advise would be greatly appreciated!

The throat in my 7x57's chamber is pretty short: Cartridges with about any lead-tipped spritzer seated just short of the lands will still fit in the 3.1" magazine. The reamer was a custom, made by Pacific Tool & Gauge for a guy I know, and when I decided to have Serengeti make a 7x57 he loaned it to me.

My rifle is still a little pickier with lighter bullets than anything in the 160-grain range, but they can be seated close to the lands and the rifle shoots them well with the right load. For a long time I shot bullets in the 156-160 grain range, but tested them enough and these days am shooting two loads, one with 140 Sierra ProHunters and one with 150 Partitions, and both shoot under an inch, the Partitions well under an inch.

Thank you for the input. When I finally get this together it will be throated To give a 160 an OAl length of 3.07" area. Ihope that makes for the best compromise.

Even more important than throat lengthi throat diameter. If you are using a parallel throat for a 7mm, diameter should be .2845 max. GD

In a recent Q&A article by another prominent gunwriter that doesn't post here (or anywhere else), a reader asked how to improve the accuracy of his 7x57. The GW suggested this and that powder and this and that bullet, but no bullet over 160 grains, and no round nose bullet at all. That floored me. The 7x57 was designed and throated for 175gr round nose bullets. Happily, my older 7x57 rifles shoot 175gr spitzers just as well. Their performance on target is exceptional, and the trajectory is flat enough for a 200 yard zero. Try it. You'll like it.

With a 200 yd zero, the trajectory of the 175 gr RN is flat enough for big game to 300 yd. BTDT a few times.

Ted

I use nothing but the 160 gr Bullet in my 7x57 build and believe the 7mm is at it best with bullet of this weight or higher , never really cared for bullets any lighter in the 7mm regardless of the case they are loaded in . The 7x57 shines with the 160 gr or 175.

bea175,

Just curious. How many different animals did you shoot with various bullets before coming to that conclusion?

I am definitely looking at a reamer print before I spend money on getting my next 7x57 barrel. JB maybe I could rent your buddy's Reamer? I know you posted a lot about the bullets you have used and I tend to agree with your choices.

Kilimanjaro Rifles owns the reamer now.

Dang, I will get it figured out. I have worked with a couple of smiths that will do exactly what the customer wants , so it should work out. But thanks for your input!

The particular reamer JB is referring to is called a 7x57 USA Match. It's one of Dave Kiff's own designs and he keeps the CNC program on file, so just call PTG and ask for it by name.

John

Only deer . I have killed maybe ten deer with the Hornady 139 gr in the 7mm RM and maybe 30 or more with the Speer and Sierra 160 gr. I just like the performance of the 160 gr better less meat damage with the 160 and the deer is just as dead. Have never used any bullet lighter in the 7x57 , the 160 gr performed the same on the fewer deer i have taken with the 7x57, dead deer and you can eat up to the bullet hole . My preference is heavier bullets in my Big Game Rifles if they they group well.

There's a big difference in shooting the 139 out of a 7 mag and a 7X57. That same bullet and plenty others in the 140 class work great at 7mm-08 and 7X57 speeds.

That's been my experience as well, though I probably would pick something in the 160-grain class if only hunting out to 200 yards or so.

Have used the 7x57 (and the 7-08, to a much more limited extent) on quite a few animals of about a dozen species in North America from Old Mexico to Canada, and in Africa, ranging in size from pronghorn and springbok to bull moose, wildebeest and kudu, at ranges out to 350-375 yards. The bullets have included Barnes TSX's, Hornady Interlocks, Norma Oryxes, North Forks, Nosler Partitions and Ballistic Tips, Sierras and Speer Grand Slams and Hot-Cors.

All the bullets worked, and about the only semi-firm conclusion I've come to is that on "deer-sized" game bullets in the 140-150 grain range kill quicker, and at longer ranges bullets like Sierras and Ballistic Tips do better.

Bullets in the 160-grain class also do well, but the tougher ones don't always kill very quickly at ranges of 200+ yards, though again a softer bullet will still do well. The 160 Sierra GameKing works pretty darn well out past 250 yards even on light game like springbok, which generally run a little smaller than pronghorns or doe whitetails.

Why does that matter? He likes the performance of his bullets on the game he shoots. Everybody knows you are a more experienced hunter than most. That doesn't mean the experience and opinions of others are invalid.

Nice, Thank you .

Big Redhead,

What the hell?

I didn't say bea175's experience was invalid, and DID specifically say I was just curious. If he prefers shooting deer with 160-grain bullets, why not? I've killed plenty of deer and other animals with 160's too.

However, this thread started because somebody else was curious about what throat dimensions would work for 140-grain bullets, because he wanted to use them. He said he'd used 160's and they worked "okay," but wanted to know the throat dimensions of my rifle because he wanted to try 140's. And in my experience 140's do work better on deer-sized game than 160's, which is why I posted my reasons for agreeing with Teeder's post.

John,

Your post sounded to me like you were discounting bea175s opinion and touting yours because your experience is broader than his.

Big Redhead,

I didn't mean it that way, just wanted to know how he came to his conclusion. I've shot a pile of deer (and deer-sized animals) with 156-160 grain bullets from the 7x57 and they work very well, given the right bullet and range. If they work for his deer hunting then that's great.