[Jon Reitz]

With everything else being equal, what difference in velocity (FPS) would you expect to see between Winchester, Fiocchi and STS primers? Serious replys only please.

 

[jimrich60]

+1 on suggs1 comments. All else being equal, changing primers will not affect velocity appreciably, but it can create significant pressure differences, in some cases, potentially dangerous increases in pressure. Manufacturers of components spend many thousands to test various loads, etc with sophisticated equipment to ensure safety, uniform velocity of a given load, patterns, etc. before publishing the data in various manuals. Stick with published data. Experimenting can be dangerous to your (and others) health.

 

[Bob_K]

The following data came from Tom Armbrust investigation on the effects of changing primers:

Shotshell Primer Comparison
Winchester 12-Ga. 2-3/4" AA Hull
17.0 Grains IMR 700-X Powder
Greenduster GT 9210-12 Wad
One Ounce No. 8 Lead Shot

Primer and Lot Velocity f.p.s. Chamber Pressure p.s.i.
Fed. 209A 03513 1251 (EV 14) 10,860 (EV 600)
CCI-209M D03C 1248 (EV 22) 10,460 (EV 1300)
Win. 209 NFL124 1246 (EV 22) 10,140 (EV 400)
Rem. 209STS 1236 (EV 16) 9,740 (EV 2200)
FIO-616 1234 (EV 28) 9,690 (EV 1600)
CCI-209 B032 1232 (EV 30) 9,650 (EV 2300)
Rem. 209P 127 1228 (EV 34) 8,810 (EV 2200)
Fed. 209 A8702 1226 (EV 18) 9,070 (EV 900)
Win. 209 MDL542 1224 (EV 30) 10,200 (EV 1700)
Cheddite 209 1217 (EV 20) 9,270 (EV 2000)

Comment: This listing is in the order of highest to lowest velocity. Maximum velocity variation between primer brands was 34 fps, while the maximum pressure variation between primer brands was 2,640psi.

 

[zzt]

John, it just depends. For instance, using Red Dot and Green Dot for my ounce and 1 1/8oz loads, there is little pressure difference and only a few fps velocity difference between STS209 and W209 primers. When using American Select pressure and velocity increase when substituting a W209 for an STS209 primer.

 

[Jon Reitz]

Thanks guys. Suggs1 actually provided what I was looking for. I always stay with published data.

 

[Shooting Coach]

The worst one generally does is to sub a cooler primer in cooler weather for a suggested load and get weak sounding shells.

Last week at a trap shoot I was scoring, one shooter had every shell sound like a box of old 410's that had been in a freezer. When he was on station three, I could usually see his shot go from muzzle to target (when he hit them). His scores were less than stellar.

I have been guilty of this myself. I bought a case of Nobel Sport primers, and subbed them for the Rio primer. In this cool weather they were bloopy, and will not be repeated.

 

[Shooting Coach]

The worst thing one generally does is to sub a cooler primer in cooler weather for a suggested load and get weak sounding shells.

Last week at a trap shoot I was scoring, one shooter had every shell sound like a box of old 410's that had been in a freezer. When he was on station three, I could usually see his shot go from muzzle to target (when he hit them). His scores were less than stellar.

I have been guilty of this myself. I bought a case of Nobel Sport primers, and subbed them for the Rio primer. In this cool weather they were bloopy, and will not be repeated.

 

[Delbert]

It's probably many years of shooting those 3 1/4 dram, 1 1/4 oz loads that caused the above flinch.

 

[Shooting Coach]

Darn. I thought this was a release mouse! LOL