308 fps question

[problemchild]

If a guy here has the exact same gun and barrel I have (18" SS lmt mws 308) and is getting 2475fps with 175smk's what ballpark fps would 155smk's be with the same or near same safe powder load?

[30Cal]

Nice looking pup. If 'm not sure if I understand the question, but if you used a 155 instead of a 175 on the same exact load, you'll be fine.

Go dig around in some loading manuals and see if you can find an overlapping powder and charge used for both the 155 and the 175. That would give you a rough swag.

[problemchild]

Nice looking pup. If 'm not sure if I understand the question, but if you used a 155 instead of a 175 on the same exact load, you'll be fine.

Go dig around in some loading manuals and see if you can find an overlapping powder and charge used for both the 155 and the 175. That would give you a rough swag.

Thanks and good idea. At some point I need a crono but my wife is balking at the pile of reloading and guns I have now. "Why do you need more" look. Women just dont understand. Everytime she wants a new pair of shoes I remind her of the gun question, "why do you need more" and she laughs.

[rsrocket1]

Check your email. I send a couple of screenshots with a hypothetical run using Varget (as good a powder as anything else). The velocities are surprisingly the same. Now if you state what your powder is and the charge, you might get a more accurate prediction of any differences.

[Fjold]

I've seen identical guns shoot the same loads with 150 fps difference. The only way to be sure is to shoot the load in your gun and chrono what you get.

Thankfully for me, Wifezilla has given up on criticizing me for any accessories that I need for reloading.

[problemchild]

I've seen identical guns shoot the same loads with 150 fps difference. The only way to be sure is to shoot the load in your gun and chrono what you get.

Thankfully for me, Wifezilla has given up on criticizing me for any accessories that I need for reloading.

My wife is pretty good about it. She caught me on a long spending streak (2 rifles, 2 scopes, reloading supplies, gun cases, bipods, bullets, primers, 50cal ammo cans, etc) and I got a question about "why so much".

She can keep a 2" group at 200 yds when she tries. I got her trained up pretty good.

Even have her carrying dead birds during bird season and cleaning fish during trout season.

[slopoke]

You need to use a chronograph when testing your loads. I used Hornadys load data for .223. The velocity measured was about 300 fps lower than the published velocities for a given powder/bullet weight combination. On the other hand, the load data for Sierra's for the same powder/bullet weight combination was pretty close. I would not have found that out without using a chronograph.