I've been working up some handloads in a 22-250 with 55 gr. bullets. Shot some Nosler and Hornady bullets with a variety of powders and came up with several pretty good loads. Velocities running about on par with the loading manuals or a bit less, as usual. Today I got out to the range and shot some 55 gr. Speers. My loads were identical to the components used in the Speer manual with the exception of the primer. They used CCI primers and I was using Federal GM210M primers {match grade primers}. Manual lists a starting load of 32.0 gr. of IMR-3031 with a velocity of 3132. I started there and my actual velocity was nearly 200 fps higher! Increasing one grain at a time, I went up to the max listed of 36.0 grains and reached a velocity of 3826 fps and a five shot group of .546"! That is 163 fps over what the book shows. I have NEVER had that happen to that extent. The barrel length listed in the Speer manual is 24", same as mine. This Speer bullet is the only one that has produced velocity higher than the manuals. The Hornady and Noslers were around 3550 fps. 50-100 fps less than the books, which is what I am used to seeing. I am wondering if there is another factor at work here and this load is somewhat over pressure.

Tedh, I would guess that the Magnum primer that you used caused the higher velocities. Nothing to worry about. My favorite loads for the 22-250 are 55 gr. Sierra spitzers with either IMR 4064, or my very favorite of 38 gr. of H380. Thats what my gun likes the best, shooting sub 1/4 inch groups. I

I use a CCI benchrest primer with the 4064, and a standard CCI primer with the H380.

3800 fps is about the norm. for the 22-250.

Steve

Tedh, I would guess that the Magnum primer that you used caused the higher velocities. Nothing to worry about. My favorite loads for the 22-250 are 55 gr. Sierra spitzers with either IMR 4064, or my very favorite of 38 gr. of H380. Thats what my gun likes the best, shooting sub 1/4 inch groups. I

I use a CCI benchrest primer with the 4064, and a standard CCI primer with the H380.

3800 fps is about the norm. for the 22-250.

Steve
That's not a magnum primer, it's the Federal Match Grade primer. I did not think they were as hot as a Magnum primer, could be wrong though.

I have noticed some going either way. Depends on brand, and I don't remember which. I do know in my experience that a CCI benchrest/match primer is a little hotter than a magnum primer. Sometimes less is best as far as grouping. With the 4064 that I use, the CCI standard primer shoots best for me anyway.

You looking for more speed, accuracy or experimenting?

The information you posted does seem a little odd. I would go back to the start load and try a different primer just to compare to. It might answer your question.
Cheezywan

There are also many other variables. Barrel manufacturer at test, and your barrel, temperature, inside case dementions and many others. Bore diameters can vary slightly causing different speeds other than what the book tells you. The book is just a guide, not always exact.

The H380 load I told you I am using had a muzzle velocity of 3500fps in the book, but when I cronographed it two years ago it was at about 3800fps. Much different.

I'll put some more together with CCI 200 primers and see what happens. I used both CCI 200's and the Federal Match primers with both the Hornady and Nosler loads and had no real difference in velocity with them. Don't see why it would only affect the Speer bullet. Max loads with the Hornady and Nosler bullets were running around 3550 fps. This 3800+ makes me a little uneasy. To my thinking, that much more speed means more pressure.

Another factor besides type of action/bbl used by the manual is that their lot of IMR 3031 is most certainly a different lot than yours. This is why reloaders are wise to begin at the start load of any recommended loading to assure they stay within good pressure parameters.

Went back to the range today and shot some loaded with both the CCI200 and the Federal match primer. average of 10 shots was a difference of 4 fps between the two different primers. I guess at this point I will have to assume that this is just a fast lot of 3031. I plan to load the same 5 or 10 cases several times and see if the primer pockets start to get loose or other pressure signs appear.

The other obvious question to ask is what chronograph you are using and were the batteries fresh? I know the Oehler 35 (no longer available) and the CED Millenium have been tested against doppler radar bullet speed readings and been shown to be very accurate. Others haven't done as well. My dad's Chrony reads 200 fps faster than my Oehler switching the same gun and load between them on the same day. These were .308 match loads running in the 2500 fps range. Nothing special. Anyway, I wanted to bring this up because we (humans) have a tendency to believe digital readout numbers as if they were absolute. These instruments can be a source of error like everything else in the testing system.

Nick

IMR3031 has changed in the last couple of years or so.so has Rx7 and someothers

Heck if it's accurate and not showing signs of pressure? Why change anything. I've gone to 8 lb. kegs instead of 1 pounders after I get a load worked up, saves redoing everything with each new pound of powder.

Do have to be suspicious of "extra" velocity...generating more vel. that expected just about has to indicate a bit more pressure than expected as well. Differnt bullets of the same weight will have different bearing areas, different diameters, and even different jacket construction...any of those factos can change pressure...which changes velocity.

Would like to find a way for the same powder charge gain velocity without gaining pressure...haven't been able to come up with a good way...****ed those laws of thermodynamics.

. . . Would like to find a way for the same powder charge gain velocity without gaining pressure...haven't been able to come up with a good way...****ed those laws of thermodynamics.

I'd rather find a way to turn lead into gold without investing in an atom smasher—and get more than just the few atoms at a time the atom smasher can come up with. Also, a time machine or reliable method of prognostication, just to get a heads-up on stock markets swings or maybe the occasional terrorist event?

Murphy's version of the four laws of thermodynamics:

1) You can't win.
2) You can't break even.
3) Things will get worse before they get better. . .
4) . . .and they're never gonna get to better.

Actually, if you use MolyFusion or Plate+ or Microlon Gun Juice to treat a bore, you will gain about 50 fps from a rifle with the same load. That's about all the bore friction is responsible for costing you. I am currently favoring the MolyFusion approach because it appears to be the most temperature stable, having no hydrocarbons or PTFE's involved. It should, therefore, have no adverse effect on accuracy or POI drift with temperature. You will probably have to find your load sweet spot over again, though, with the barrel time having shortened a little. Let us know how it works for you?

Nick

Depends on the load..have had moly bulleted loads LOSE velocity. The bullet pull value went down; without the same amount of resistance, some slower powders just don't burn the same at ignition, and can end up with a slower moly load....and the moly seems to stay in case necks a good while after you stop using moly coated bullets.


Can assume the presure also whent down with the reduced bullet pull....it would be an assumption, and I'd not care to boose the powder charge just on tht idea.

Didn't show up with medium to fast burning powders, so am just guessing that the initial resistance was less with the slick-bullets and that that casued the lower speeds.

. . . have had moly bulleted loads LOSE velocity. . .

This isn't related to barrel lubrication, which will always increase velocity. You can see test results on the Sprinco (http://www.sprinco.com) web site.

Moly coated bullets, on the other hand, almost always lose about 50 fps on a load. Three explanations of this are circulating in the literature. The most common one is probably wrong. It is that the lubricated bullet engraves onto the rifling with too little resistance to provide adequate back pressure to sustain the powder burning rate. The fact barrels lubricated as I described cause even commercial rounds to gain about 50 fps suggests this is wrong. The lubricated barrel lets a bullet get on the rifling more easily, too. I have heard plain bullets seated in their cases, then sprayed with Ms Moly on the tips do not exhibit velocity loss. If true, that would be final proof, since the sprayed moly will lubricate the rifling start. I want to test this for myself.

The second explanation for moly bullet slow-down is in Harold Vaughn's book Rifle Accuracy Facts. He did an experiment in which he put a tiny amount of moly directly on top of the powder charge in a case, then seated an uncoated bullet over it. He got the same 50 fps loss in velocity. He chose the tiny amount of moly to equal what he estimated was exposed to the powder on the base of a seated moly coated bullet. In his model, the moly is acting as a phase change material, absorbing just enough of the heat of the explosion as it melts to reduce combustion temperature and slow the combustion rate. A corresponding reduction in chamber pressure appears.

The third explanation says that Vaughn’s estimate of the moly quantity is incorrect and too high. This school believes that the copper in the brass and the bullet gilding metal form a relatively high frictional bond as it sits (the one responsible for the static coefficient of friction being higher than the kinetic coefficient of friction). In this school, the moly on the bullet that isn’t scraped away during seating is preventing the bullet and case neck from achieving their usual contact intimacy. This makes it easier for the brass to separate from the bullet surface under pressure and makes it possible for the bullet to start moving and engraving onto the rifling earlier in the pressure curve, thereby reducing combustion pressure and temperature. The bottom line here is lower start pressure.

As I mentioned to you in another thread, the pitch used to seal military bullets in place is known to increase start pressure and improve powder combustion consistency. Accuracy is improved, thereby. If theory three is correct, it should do the reverse and you would expect a slight deterioration in accuracy for most loads when a moly bullet is used. This is exactly what Sierra’s Kevin Thomas found in his tests of moly bullets published in Precision Shooting. The reduction was very slight, but measurable.

These theories are pretty easy to test. I will be doing some testing of them and of firelapping and barrel lubrication later this year. I have about 90% of the necessary equipment lined up and will let the forum know what I learn?

Nick

That makes sense.

Did test Moly...didn't find naything to make me want to switch...for those that do, I've no complaint with their choice, it's just not something that seemed for me. Perhaps if the riflesw were newere, less broken in, but for my style of shooting it's somthing I prefer not to deal with.

Agree with rs - tried the moly for several years and went back to uncoated bullets. Never could establish all the claims about increased accuracy, less barrel wear and lower pressures. Did find a dramatic loss in velocity, though.

The nasty stuff sure found a way to coat everything else in the gunroom, too! :(

I am wondering about the manufacturer of the powder. IMR is now made by Hodgdon. Have you recently made a switch in lot numbers? I had an experience not so long ago that went the other way in velocity. Could see it in volume of a charged case.
I know that you said it was with the Speer bullets, I am just fishing for clues.
Cheezywan

I am wondering about the manufacturer of the powder. IMR is now made by Hodgdon. Have you recently made a switch in lot numbers? I had an experience not so long ago that went the other way in velocity. Could see it in volume of a charged case.
I know that you said it was with the Speer bullets, I am just fishing for clues.
Cheezywan
No, this is an older can of 3031 that I have had for 3-4 years. Bought it to try out on some other project and have not used any more till recently on this 22-250.
I have decided that I am not comfortable with this load, and will reduce powder charge till I get around 3600 fps and see if the accuracy is still there. If it is then that is where I will stay. If not, I have three other good loads with the other bullets and powders.