I need some help please

[ovenpaa]

This is a very poor cross section of the side elevation of a rifle bolt and the bolt face. (A front locker two lug if you look carefully) It does not have an ejector or firing pin but hopefully you get the idea

I need some dimensions from a few bolt faces for a measuring tool I am working on and would like to know:

Rifle make/model
Cartridge
Dimensions A, B & C

So if you still have the rifle out from cleaning after today’s shooting, or are bored with TV and have a couple of minutes and a vernier I would be very grateful. :goodjob: :goodjob:

Bolt.png (9.23 KiB) Viewed 1171 times

[AL8]

ovenpaa
hopefully this will help

rifle = schmidt rubin model k31
cartridge = 7.5x55
A = 1.45MM
B = 12.84MM
C = 21.71MM

option 2 bored with the telly

[ovenpaa]

Brilliant, that is a good start many thanks.

[AL8]

your welcome

[John25]

Metric or propor engineering measurement?

If God had wanted us to be metric, there would be ten disciples!

[ovenpaa]

Either is good John, the important one to me is the depth of the seat for the case head in the bolt face however that is also going to be the hardest to measure accurately. Right now I am not unduly fussed by a couple of thou either way. I have a depth DTI I used for checking my own bolts however I would like to get another half a dozen or so checked as well.

If what I am trying to achieve is proved to work then no doubt I will be pouncing on people at the range over the next few weeks and asking them if I can measure their bolts

[John25]

I'm off to murder a few clay targets in a mo. I'll do a couple when I get back ' though I suspect you have .303 and .308. I have 6.5/284 ( but that's .308) if its any good?

[ovenpaa]

The .303 is rimmed so not needed however more .308/7,62 and 6,5-285 will be good as I am looking for variances between Action manufacturers.

[1066]

Here's another one for you -
Savage 12F - 6.5x284 (.308 size)

A = 2.83
B = 12.02
C = 17.51

Measurements taken with a digital caliper, so give or take a bit.

[Robin128]

Rifle make/model Cartridge Dimensions A, B C
Remington 700 308win 0.15" 0.475" 0.695"
Remington 700 223rem 0.1425" 0.400" 0.695"
CZ452 22lr 0.0325" 0.275" 0.705"

HTH