Blowing out primer at below recommended start load 300WM

[windfall]

fghjfh

 

[stacy]

Look you can build higher pressures with reduced loads as well as loading well or max loads be carefull loading at reduced loads I know your just 1gr under starting load but all powders are different .

 

[280man]

Maybe your throat is to short for these bullets and you have to much bullet in the case?

Are you 100% sure you have RL22?

 

[Toby Bradshaw]

Norma brass in 300 WM is often much heavier/thicker than that from other manufacturers. Do you have any chronograph data for your loads? You may well find that you are getting plenty of velocity with smaller charges because of the lower case capacity of the Norma brass.

 

[wapiti25]

I would check your scale for the 66gr setting then check the scale with a calibration weight.

 

[artbosco]

Looking for advice on why loads are too hot even though I'm BELOW the recommended start load on my 300WM.

I'm using Berger's manual for 210 gr VLD target (page 767). I'm using:
-RE-22
-New Norma Brass
-210 Berger VLD Target
-Standard blue box Federal primers

Book says start load is 67.5 with a max load of 71.1. I'm at 66 gr and blew out 3 of the 26 rounds I shot today. ALL of them show signs of high pressure with a dent from the extractor.

I started getting this problem when I switch from Berger 210 BTLR to 210 VLDs. Naturally, I re-measured the ogive off the lands and reset the bullet seating die appropriately. What am I doing wrong?

I'd start with the Bullet Techs at Berger and the Powder Techs at Alliant. That's their livelihood. No ones going to know better on how to solve or explain your problem than they are. Start with the experts!

 

[dkhunt14]

Years ago I got a lot of R22 that was really hot. Lot #25083. This lot was so hot I was down 6 grains and still blowing primers out of the case. This was in a 308 Baer and I called my gunsmith and he said don't go any lower because of secondary ignition. I called Alliant and they said they knew that lot was hot. From all the cases I lost and the damage to my bolt I decided to switch to Hodgen powder and never went back.

 

[expiper]

sounds like you may have shot/loaded the brass enuff to get a donut and you are seating the bullets far enuff into the case neck to swell the neck out and pinch it in the chamber,,,esp since it is "custom"so it maby be "tite" enuff to cause problems,, ,,,which will skyrocket the pressures no matter how mild the load,,,,Roger
PS...try some other powder ,,,NOT Rx-22,,,see if it still does it !!!...and forget the length to the ojive,,,how much are you pushing into the neck???? that is what get you into donut problems,,,,measure the neck dia. at the shoulder and see if it is fat/tite and is it scuffed up when you chamber and then extract a round un-fired...

 

[tuttlefarm]

Check you neck clearance.

 

[madderg]

under-loading a rifle cartridge, especially a large one will make a bomb. You leave to much open space inside the round as the powder lays flat in the case on its side leaving the expanding gasses to explode both out the neck and out the flash hole with to much empty room inside. The 264 mag was notorious for this same thing.

 

[CatShooter]

under-loading a rifle cartridge, especially a large one will make a bomb. You leave to much open space inside the round as the powder lays flat in the case on its side leaving the expanding gasses to explode both out the neck and out the flash hole with to much empty room inside. The 264 mag was notorious for this same thing.

It does not work that way. How the powder lies has nothing to do with anything.

 

[madderg]

There has been studies done on under loading large mag cartridges, and bad thing can and do happen. It does not happen all the time, but it's always best to be safe...if you want to reduce load do it with fast burning powders. ALWAYS be safe.

 

[Webster]

OP QUOTE:

Looking for advice on why loads are too hot even though I'm BELOW the recommended start load on my 300WM.

I'm using Berger's manual for 210 gr VLD target (page 767). I'm using:
-RE-22
-New Norma Brass
-210 Berger VLD Target
-Standard blue box Federal primers

Book says start load is 67.5 with a max load of 71.1. I'm at 66 gr and blew out 3 of the 26 rounds I shot today. ALL of them show signs of high pressure with a dent from the extractor.

I started getting this problem when I switch from Berger 210 BTLR to 210 VLDs. Naturally, I re-measured the ogive off the lands and reset the bullet seating die appropriately. What am I doing wrong?

thanks in advance


The reloading manuals are just a guide not absolute. Every rifle is different. Just back off on the powder charge. I think the Sierra manual is more conservative than the Berger. The Sierra start load is 3-5 grains less than the Berger manual for similar weight bullets. Seating depth, bearing surface, neck tension ect. will affect pressure.



Corrected data numbers from my original post. Same thing VLD has a longer bearing length.

The VLD has a longer bearing surface. More resistance to pushing it down the bore.
Berger manual p. 241
210 gr LRBTHP (base to ogive) .628" Bearing surface .438"
210 gr VLD (base to ogive) .730" Bearing surface .540"

The Sierra Manual data:
200 gr. HPBT MK RE-22 63.6 2600 fps max 72.3 2900 fps
220 gr HPBT MK RE-22 61.5 2500 fps max 68.1 2700 fps

Good Luck

 

[JohnnyJohnson]

Thanks for the responses.

I'm certain it's Alliant Reloader 22. That's all I have.

So, does the chamber pressure increase or decrease in relation to the distance the bullet is off the lands? I should be right off the lands. Maybe I'm too far off the lands? Maybe I measured it wrong.

How old is this powder a few years ago Alliant put out a really hot lot of RL 22 that guys had the same problem with you're having.

 

[searcher]

I wouldn't want to be the one to see you increase a load at this point and risk blowing up your rig without consulting with Alliant- but a few of the loading manuals make note that when using a slow burning powder and using a lower-than-recommended starting charge - chamber pressures spike to the point the recoil can literally shatter the wood stock of a rifle. In one of the recent Barnes manuals, I had plenty of one of the three powders listed on hand for their 235 grain TSX load for a .375 H&H Magnum. I've owned that Sako a long time and wasn't ready for the unwelcome surprise I got when firing the first load at minimum charge. If there is a point you think a gun couldn't take any more without blowing up - I think I was there. Barnes has since issued a warning not to use that powder. This was an example of what Speer had mentioned in one of their manuals in respect to undercharging .243 loads with slow burning powders and heavier bullets- don't do it.

I use Reloader 22 in my 7MM Remington Magnum (Bat repeater action with Krieger Barrel) and nothing shines like this powder - not even close. I might contact Alliant and pose your load to them for their comments on this. Could just be too LIGHT of a load. Of course, the last thing that seems rational is to add more powder when you are experiencing what you are with the primers. Nevertheless - I'd contact Alliant before moving on.

 

[searcher]

I forgot to add in that you should NOT try reducing the load until checking with Alliant - as that may make the situation worse - with higher chamber pressures. Reducing the load on this slow burning powder can have the same adverse effect as increasing over what is recommended as I discussed above. Check with Alliant before increasing OR decreasing.

 

[243hart]

Hi,

There are two diffrent weights on the 300WM cases from Norma, depending on when they were manufactured. 215 gr and 270 gr.
Weigh your cases. There might be up to 6 gr difference in max charge between the two types.

Regards
Emil - Sweden

 

[ThunderDownUnder]

High pressures from low charges are documented in a number of places and its rare but does happen! Follow this link on a 300WM wildcat and the gunsmith writting the article gives his opinion on what he thinks causes it.
http://www.ballisticstudies.com/Resources/Articles/The+7mm+Practical.++A+Practical+Magnum..html

Ian

 

[Webster]

I see a lot of post stating something like your already at or near the minimum charge of RE-22 and going below a Berger starting charge of 67.1 might cause excessive pressure. A different bullet: for Sierra's 220 grain bullet the starting charge is 61.5 grains of RE-22. You have to remember that in most cases the manufacturers data was collected with one rifle. People like Berger probably have pressure strain gauges on the barrel when they test.

Most reloading manuals tell you to start with 10% less powder than the max charge in their data. 90% of 71.1 is 64 grains not 67.1. My guess is that 62 grains for a starting load isn't excessively low. It shouldn't be called a reduced load? Try 66.5 then 66.0 and see what happens. People have sent you and endless list of possibilities. The powder charge is the most obvious and easiest to try. Chrono data at lighter charges might make you feel better if the fps are up there.

 

[Raythemanroe]

Deflagration vs Detonation: (I would start off with saying the Tech at Burger is the best advise I have read yet given) As far as I know and have seen (one gun Detonate) under loading your reloads is more dangerous. I have seen a 6mm Rem (not mine) under loaded and make a weird sound (more of a pop) and the primer was blown out and the case had to be forced out..I then researched this and found that powder is designed for deflagration or to burn and build pressure throughout the barrel. When under loading during the ignition process there is a chance of igniting the powder at once and therefore detonating and building pressure to rapidly. At what point this can happen I would guess it varies and could never recommend a under load for anyone..I wouldn't think it would be like increasing your load and tracking pressure signs and velocities because once you reach detonation the $hit hits the fan.