Home Forums Classifieds Blogs Today's Posts Search Social Groups


Glock Talk
Welcome To The Glock Talk Forums.

Thread Tools Display Modes
Old 05-09-2014, 14:37   #1
Senior Member
Gpruitt54's Avatar
Join Date: Jul 2012
Posts: 678
+P loads with reloading equipment!?

I am a bit curious about what goes into a +P load if done by a reloader. Not going to try it myself. But, can a home reloader make these loads (safely!)? The reloading books expressly warn against exceeding powder weights, so how does the ammo makers do this and how is it different with home reloading gear? Is it different cases, special powder, or what?

I am sure this question has been asked thousands of times on this forum. So, sorry for rehashing a very old topic.
Gpruitt54 is offline   Reply With Quote
Old 05-09-2014, 15:01   #2
F106 Fan
Senior Member
F106 Fan's Avatar
Join Date: Oct 2011
Posts: 5,797
All that is required is a way to measure pressure and hobbyists have no such equipment.

There is a SAAMI maximum standard pressure and, generally, +P will be 10% higher. All the ammo manufacturers need to do is a little math and a bunch of testing. And buy a LOT of insurance!

Clearly, they need to account for ambient conditions, powder measure variations and a lot of other factors but, conceptually, there's nothing to it once they have a way to measure pressure.

"No matter how cynical you become, it's never enough to keep up." - Lily Tomlin
F106 Fan is offline   Reply With Quote
Old 05-09-2014, 15:11   #3
Join Date: May 2014
Location: Greenacres, FL
Posts: 88
For the home reloader, without the gizmos to scientifically measure pressure, going from recommended starting loads to maximum recommend, and then a grain at a time, watching for primer flattening and the like, would probably be how to go about.

Not something I'd ever do either. I began reloading in the 1970s to load 44 magnum cartridges down to a level I could enjoy shooting them at. The factory fodder was too hot for my wrist and elbow.
Jimmy10mm is offline   Reply With Quote
Old 05-09-2014, 15:12   #4
Senior Member
Gpruitt54's Avatar
Join Date: Jul 2012
Posts: 678
Interesting. So nothing special about the brass, only the powder required to produce the desired pressure.
Gpruitt54 is offline   Reply With Quote
Old 05-09-2014, 15:47   #5
Senior Member
dougader's Avatar
Join Date: Apr 2004
Location: OryGun
Posts: 3,385
If you look at the Starline brass website you can read about 9mm and 45 auto +P brass. IIRC, the brass may be tougher, but also have less case capacity so in some cases just using +P brass can raise pressures a bit.

Not all +P brass is treated equal. You have to research everything for your caliber, your brass, etc.

The thing about reloading is that even if you use the same components as listed in a reloading manual, their maximum listed load may result in loads that are higher than SAAMI maximums for you, in your gun. Always start below max and work your way up.

"In St. Louis, armed Homeland Security agents monitored Tea Party members protesting the IRS. Good idea. When people think their government is out to get them, the best response is to send the government out to get them." -Fred Thompson
dougader is offline   Reply With Quote
Old 05-09-2014, 16:14   #6
Senior Member
fredj338's Avatar
Join Date: Dec 2004
Posts: 21,642
Blog Entries: 3
Most ammo manuf do NOT use canister powders, but have their own blends made. So for the reloader, you are stuck with book data. There is the rub, one book says this is max, another is 1/2-1gr higher for max. So it will depend. If you can read pressures, understand the chrono data, then you can go over some book data to achieve +P vel.
"Given adequate penetration, a larger diameter bullet will have an edge in wounding effectiveness. It will damage a blood vessel the smaller projectile barely misses. The larger permanent cavity may lead to faster blood loss. Although such an edge clearly exists, its significance cannot be quantified".

Last edited by fredj338; 05-09-2014 at 16:14..
fredj338 is offline   Reply With Quote
Old 05-09-2014, 17:03   #7
Senior Member
Join Date: Nov 2011
Location: PRK
Posts: 1,512
There are some SAAMI +P specifications, usually with calibers that came along before smokeless powder (but not always). These +P pressures are usually 10% over max for the non-+P spec for that caliber.

Some manufacturers publish load data for some of the +P specs. Hodgdon publishes loads for some +P caliber specs, so there is no problem using this data. You should use +P spec brass as some very old brass for the non-+P caliber may or may not hold up to the higher pressure (probably will).

You will see some manufacturers use terms like +P or +P+ for ammo they make in calibers that don't have a +P SAAMI designation, all these guys are saying is the load may be over max pressure for a normal load in that caliber (40S&W seems to be a favorite for this kind of marketing hype). When they publish +P+ they are saying is "please buy us for a $1 a round we really need the money..."

I have loaded over book spec on purpose and a few times by mistake, in the end you generally find out that the guys that designed these things in the first place knew quite a bit about the objective at hand and designed things to be optimized to that pursuit.
Audentes fortuna iuvat
WeeWilly is offline   Reply With Quote
Old 05-09-2014, 17:20   #8
Senior Member
Join Date: Aug 2003
Location: Kentucky
Posts: 419
While I'm not recommending anyone load into the +P pressure levels there is published data available for +P loading. I would only recommend using published data using the exact components listed and the exact overall bullet seating lengths. AND the most important safety measure is to ONLY use new unfired cases every time. Never multi-fired cases or unknown source brass. Your firearm should be rated for +P levels. Plus every powder charge should be weighed on a verified scale. I don't see the benefits to try to push a 45 ACP another 50 fps just to say you're loading +P or trying to push 9MM or 40 SW another 50-75 fps.
rg1 is offline   Reply With Quote
Old 05-09-2014, 17:40   #9
WiskyT's Avatar
Join Date: Jun 2002
Location: North Carolina
Posts: 11,755
As a practical matter, reloaders can very often duplicate or even exceed +P velocities by using published non +P data. For instance, Speer/Alliant publish 5.8 Unique with a 124 JHP in 9mm. This is not +P data. But, I can assure you that the velocity will duplicate the 124 GDHP +P load all day long.

Also, as others have mentioned, there is some true +P data published by reliable sources. The only +P data I have seen published is for 38 Spl and 45 ACP.
Drugs are bad because if you do drugs you're a hippie and hippies suck.
Eric Cartman

"If you kill enough of them, they stop fighting."-General Curtis E. LeMay
WiskyT is offline   Reply With Quote
Old 05-09-2014, 19:47   #10
Grumpy Old Guy
DWARREN123's Avatar
Join Date: Jan 2008
Posts: 4,097
Also remember that ammo producers get bulk or designed powders and can do things most reloaders can not.
Have a Nice Day
DWARREN123 is offline   Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -6. The time now is 02:16.

GT Wiki
GT Blogs
Social Groups

Users Currently Online: 632
123 Members
509 Guests

Most users ever online: 2,244
Nov 11, 2013 at 16:42