I have a few questions for you guys to answer,
1) Does seating the bullet .005 off the lands change velocity as opposed to seating .020 off the lands?
2)Does a light crimp make velocity slower as oppossed to no crimp?
3)I shot some reloads with my 7mm rem the other day, it was -15c or a 5f (cold) my loads were
RL22 66.5gr with 140 accubonds out of a 26" barrel,Sauer 202, my average speed with these loads was 2975fps.The Nosler book list that laod at 3240fps with a 24' tube, WHY THE BIG DIFFERENCE does the cold affect the velocity that much or is my barrel a bit slow? It is a new gun this was the 2nd time at the range with it.
Sorry for all the questions guys
Thanks
Elmer

As far as I can tell I`ve never seen a crimp or change in seating depth vary the velocity of a load.
The cold may have had something to do with the slower velocities you found, I have seen that occure with my loads at times. The book also isn`t always comparable to your rifle when it lists velocity. There are too many variables to try to keep matched when copying a load to match the labs result exactly. The combination of cold temp and the difference in components from the ones used in the manual probably accounts for your findings.

Originally posted by elmerdeer:

1) Does seating the bullet .005 off the lands change velocity as opposed to seating .020 off the lands?

It can but the changes would be subtle if present. The closer the bullet is to the lands, the higher the pressure, however, but mostly when at the lands.

2)Does a light crimp make velocity slower as oppossed to no crimp?

The short answer is No. But you are only asking about one variable of many, so it is possible.

3)I shot some reloads with my 7mm rem the other day, it was -15c or a 5f (cold) my loads were
RL22 66.5gr with 140 accubonds out of a 26" barrel,Sauer 202, my average speed with these loads was 2975fps.The Nosler book list that laod at 3240fps with a 24' tube, WHY THE BIG DIFFERENCE does the cold affect the velocity that much or is my barrel a bit slow?

First you must learn this: Nosler manual velocities are the simplest definition of EMBELISHED. Every bore is different. However, your temperature is significantly colder than what is published in most manuals. I think most of them are closer to 70 degrees.

The colder the temp, the lower the velocity.

Everyone above has given you perfect advice.

I ran your load past quickload and it agrees very close to your results.

It thinks if you ran that load in 70 degree weather it would have done 3118fps at 51k pressure.
In 5 dgree weather it thinks it would be doing 2998 fps at 45k pressure.
You probably can work up to get a bit more speed. Work up in .5 grain increments and watch for accuracy.....change of impact....and pressure.

quote:

Originally posted by elmerdeer:

1) Does seating the bullet .005 off the lands change velocity as opposed to seating .020 off the lands?
2)Does a light crimp make velocity slower as oppossed to no crimp?
3)I shot some reloads with my 7mm rem the other day, it was -15c or a 5f (cold) my loads were
RL22 66.5gr with 140 accubonds out of a 26" barrel,Sauer 202, my average speed with these loads was 2975fps.The Nosler book list that laod at 3240fps with a 24' tube, WHY THE BIG DIFFERENCE does the cold affect the velocity that much or is my barrel a bit slow?

1. Not in my experience. I just recently did a test of 6 different loads at .005", .010", .015",.020", .025" and .030" off the lands. The loads were identical other than that. There was no noticeable and significant change in velocity.
2. Yes in my experience. I have done 3 different tests with loaded-at-the-same-time shot-at-the-same-time identical loads except for a medium crimp with the Lee Factory Collet and in all 3 the velocity increased approx. 10 fps with the crimped loads. Not significant, but consistant.
3. The cold and the rifle probably both contributed to the slower velocity. Some rifles need a heavier load to reach the velocities listed in the manuals. I would say, most of the time.

elmerdeer, altitude/baro presure/temp/ moisture or density can play a part in the velocity of a rond. they don't tell you all the load paramiters of the loads when produced. just for grins, load some up when its low humidity, 70-80degrees and at where ever you are them shoot half then so to higher elevation cold and denser air use a chrony. you'll see a diff in velocity. we have done this here in north cal. . just my long winded .04 worth. Dave
ll see a diff.

The easy way is to find the most accurate load for the conditions and ignore the books and chronograph. Trying to match book velocities will neither make the gun kill better or shoot more accurately.
After you get the accuracy you want, then chrono it for your records and be happy with what you get.

in my experience the reloading books are fairly optimisitic. myself and people i know have found that you have to stick in a few more grains to get the velocity they claim

quote:

Originally posted by bfrshooter:
.... Trying to match book velocities will neither make the gun kill better or shoot more accurately. After you get the accuracy you want, then chrono it for your records and be happy with what you get.

Excellent post.

elmerdeer,

That's a rather light load with 140s. My advice is to ladder up to around 70+ grains and closely monitor classic pressure signs as well as your accuracy.

Every rifle is different and most will produce differing velocities when using the same loads.

Good Luck

Reloader