newbie w/ questions

[Rentedmule]

First of all thanks to all who post and help us new guys here. I have learned a ton reading this and other forums. I have just got my 550B set up and loaded my first 223s. I am taking it very slow as I do not have a mentor locally to help.

Three questions I have either not been able to find the answers to or have read conflicting information.

1) Do you need to or should you crimp rifle cases if they are to be used in bolt rifles only? The bullets do not have a cannelure.

2) When checking the powder charges I am getting a variance of 0.2gr between drops consistently with a 0.3gr difference every tenth round or so. I am using H335. Is this normal and acceptable? I am checking the charges on two separate scales and while a slight variance between scales is present, it seems that could be explained by both scales being accurate only to the 0.10gr.

3) How do I adjust my load if using a small pistol mag primer vs the small pistol primer called for on the 9mm load? I have the mag primers and cant find the small pistol. Will be using Tightgroup powder most likely if that matters.

Thanks

[Sterling White]

I'll give your questions a shot ....

Question 1 - no, typically a round being loaded from a bolt gun is less likely to put pressure on the bullet causing it to be set back further into the case during the loading process. So I wouldn't worry about a crimp. What I would focus on is the overall length of the round. You will want to load the round just long enough so that the bullet is almost touching the lands.

Question 2 - not a big deal if you are loading within the specifications of the manual. If you are loading a max load then its cause for concern. If your looking for precision then it you may wish to weigh each charge on a scale.

Questoin 3 - I would not adjust. Stick with the load from the manual and look for signs of pressure on a few test cases and primers. If there are no signs of pressure then compare the rounds on a chronograph to see if there is any variation in bullet speed. The min. power factor for the 9mm is 125000. You get that by multiplying bullet wt x bullet speed. No need to push out high power rounds if your shooting ipsc or uspsa.

Keep a look out for primer news on the forum. Someone usually adds a post where we can go to get primers and when.

Edited December 15, 2009 by Sterling White

[calishootr]

on the .223, if only being used in a bolt gun you dont really need to crimp, so dont worry about it, as forthe 3 tenths variation on powder charges using H335??? thats strange because H335 meters like water...you should only be +/- 1 tenth, which is pretty much within specs forthe 550b's powder measure, with 3 tenths variation, you will see bigger groups because of the lack of consistency, especially as you stetch out the distances to the target...

Me personally, im not a big fan of magnum primers in a 9mm case, there just isnt any room for a fudge factor in that little case, with nominal pressures being in the 35,000 psi range...changing to a magnum primer is not a good idea, especially if you are experienceing a 3 tenths variation with your powder measure??? ut uh....not me....least not run the same charge as with regular small pistol primers, I would back off at least 2 tenths, and run em over a chrono, just to be sure...

[3quartertime]

Welcome to the forums!

[boz1911]

First welcome to the forum

Is your 550 new ? If so the powder measure should settle down a bit after everything smooths out. I usually check powder charges by weighing ten then divide.

There will be no problem using magnum primers but I would back down the charge a bit and find a chrono. Remember a lot of us are shooting 9mm major with power factors well above 170.

[Duane Thomas]

The min. power factor for the 9mm is 125000. You get that by multiplying bullet wt x bullet speed. No need to push out high power rounds if your shooting ipsc or uspsa.

You do want a bit of a cushion to ensure you make power factor at the chrono station, so yes, there is a reason to push for higher power. Most people go for a 130ish power factor.

[Duane Thomas]

Me personally, im not a big fan of magnum primers in a 9mm case, there just isnt any room for a fudge factor in that little case, with nominal pressures being in the 35,000 psi range...changing to a magnum primer is not a good idea, especially if you are experienceing a 3 tenths variation with your powder measure??? ut uh....not me....least not run the same charge as with regular small pistol primers, I would back off at least 2 tenths, and run em over a chrono, just to be sure...

A 130 power factor load is considerably under factory 9mm ballistics which tend to go around 140. Also take into account the 9mm Parabellum has an ungodly strong casiing with very thick web. This only makes sense - it was originally designed to run at pressures that in the U.S. we would consider +P+. We are not running even close to the edge with our Minor power factor handloads. I have substituted Magnum primers for standard primers in my match loads without a single problem.

[chirpy]

Rentedmule, welcome to the forum. I suggest you get a good reloading manual or 2 and read what they have to say. The terms used to discuss rifle rounds versus pistol rounds are a bit different as was explained to me. Some say this is splitting hairs and others think it is very important...doesn't much matter to me! The bullet in a rifle round is held by tension (not crimp) of the case neck after the brass is resized and the neck expanded. This can be adjusted by swapping out for different sized expander buttons if necessary. You should have little trouble with newer quality dies. Also. as stated above OAL is important in a bolt gun. A variation of .3 gr. is only a problem if top accuracy is the goal and or if you are using max loads.

FWIW & IMHO

Richard

PS: If you want to see pickey, just check out Benchrest competition! They go to extremes and their equipment and groups show it!

[Rentedmule]

Thanks for the replys guys.

I think I may have figured out some of the powder variance problem. I noticed some small amount of powder was sticking to the inside of the neck maybe due to some of the spray lube getting in there. Don't know if it will be that much but it cant help consistency. Will try a "dry" case tonight and see if it still sticks in there.

I will probably wait until I can get some non magnum pistol primers but after building the bench, ordering the supplies, reading everything in sight, and setting up the machine, I am getting impatient. I am going to start with the minimum load anyway for the first group but I don't want to start off coloring outside the lines.

Once again thanks, I'm sure I'll be bothering y'all again