7X57 170 Grain Sierra RN

[Corjack]

(Cartridge) 7X57 Mauser

(Brand of bullet) Sierra

(Weight of bullet) 170 Grains

(Brand of brass) PRVI

(Type of powder) Hodgdon H100V

(Grains of powder) 47

(Brand, and type of primer) Winchester LR

(COL) 3.170

(FPS) Unkown

(Rifle) Blaser R93

(Barrel Length) 22 inches

(Scope) Swarovski Z6 3-18X50

(Weather conditions & temp.) 60 degrees and a tad breezy

(Accuracy @ 100 yards/meters) under .5 MOA


(Notes)

I have been trying to develop a load that has several goals.

Use up the 1600 plus 170 grain Sierra bullets I have on hand. Use a powder that I have a lot of on hand. Seat bullets to under the max length that would run through the 7x57 magazine for an R93.

I ran about 75 rounds through this rifle the last two days, playing with about six different powders. Played with seating depth, but never longer than what would fit through the magazine. Best I ever got was about two inches with H4350. All others looked like buckshot patterns.

Finally yesterday, I said screw it. Grabbed the next longer magazine, that fits the 8x57, and the 6.5x55. Dropped it in, seated bullets out to fit the mag nicely, and instantly things went down to 1.5 inches. This morning played with powder charges, a bit, increased a couple times, was getting inch to inch and a quarter groups. went up a tad more in powder, and shot this three shot group. The bullet with the x in it, was from another pattern. Loaded up four more rounds, and it took three shots to range the 400 yard gong.

I was a bit surprised how flat it was shooting.

Will play with it a bit more the next couple days, to see if it is consistent.

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[mchughcb]

Looking good.

[Saugmann]

Well done. Interesting how much the seating depth matters. Thanks for sharing.


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[Corjack]

Here are a few more thoughts.

This bullet is a discontinued bullet by Sierra. I am not sure they even had the 7x57 in mind when it was designed. It is fairly pointy for a bullet of this weight, and also being a round nose design. Casual observation also it appears to have a short bearing area for it's length. All the bearing area is toward the rear. May explain why it really likes to be seated out long, as if seated to the cannelure, it has to jump about .375 inch before hitting the lands.

[Gun Barrel Ecologist]

Interesting to see how they go on game.

I gather there is no cannilure on the bullet to indicate suggested seating depth as there is on the 175g RN interlock?

[Corjack]

Interesting to see how they go on game.

I gather there is no cannilure on the bullet to indicate suggested seating depth as there is on the 175g RN interlock?

Yep, there is a cannelure. Will post a picture in a bit.

[PerfectShot]

(Cartridge) 7X57 Mauser

(Brand of bullet) Sierra

(Weight of bullet) 170 Grains

(Brand of brass) PRVI

(Type of powder) Hodgdon H100V

(Grains of powder) 47

(Brand, and type of primer) Winchester LR

(COL) 3.170

(FPS) Unkown

(Rifle) Blaser R93

(Barrel Length) 22 inches

(Scope) Swarovski Z6 3-18X50

(Weather conditions & temp.) 60 degrees and a tad breezy

(Accuracy @ 100 yards/meters) under .5 MOA


(Notes)

I have been trying to develop a load that has several goals.

Use up the 1600 plus 170 grain Sierra bullets I have on hand. Use a powder that I have a lot of on hand. Seat bullets to under the max length that would run through the 7x57 magazine for an R93.

I ran about 75 rounds through this rifle the last two days, playing with about six different powders. Played with seating depth, but never longer than what would fit through the magazine. Best I ever got was about two inches with H4350. All others looked like buckshot patterns.

Finally yesterday, I said screw it. Grabbed the next longer magazine, that fits the 8x57, and the 6.5x55. Dropped it in, seated bullets out to fit the mag nicely, and instantly things went down to 1.5 inches. This morning played with powder charges, a bit, increased a couple times, was getting inch to inch and a quarter groups. went up a tad more in powder, and shot this three shot group. The bullet with the x in it, was from another pattern. Loaded up four more rounds, and it took three shots to range the 400 yard gong.

I was a bit surprised how flat it was shooting.

Will play with it a bit more the next couple days, to see if it is consistent.

image.jpg

image.jpg

Hello,
I love the 7x57 Mauser and shoot this cartridge in my original 1933 civilian Mauser rifle and in my modern Blaser K95. With great success. I load my cartridges myself and achieve very good precision (Sub MOA).
This is my loading data: