Don't Use Mid Loads In A New Rifle Without Checking

Joec7651

Handloader
Apr 7, 2019
926
1,233
By my own complacence I learned a valuable lesson. Don't fire even mild loads in a new rifle without checking chamber dimensions!

I took a new 7mm RM to the range with mild Partition loads for its first firing. Rounds chambered fine, and the first 3 rounds split the necks. Turns out the Partition bullets were jammed into the rifling even with SAMMI specs. They were not top end loads by any means but the fact that the bullet was jammed into the rifling raised pressures to the point that it split the necks of the first three rounds fired. Primers were still round but the necks split non the less. After having the rifle checked by a smith its fine, but learn from my carelessness. Verify that your loads fit your chamber and throat before firing, even if they are mild loads in another rifle. The fact that they were mild loads was the only reason nothing went terribly wrong. I've been loading for 30+ years and know better. I got complacent. I was stupid and very lucky. There was no indication with recoil or muzzle blast but the outcome could have been much worse. I thought the rounds would be completely safe because they were mild loads. I did not however check what the COAL for that rifle should be. Learn from my mistake. I was lucky, another may not be so fortunate. Just a reminder to not take things for granted when we load.
 
Thank you for sharing.

I measure the chambers with the Hornady gauge tool. I noticed a 300 wsm my son has has a short throat. If I load SAAMi, I’m in the rifling. I received the brass and about 50 handloads from the previous owner, lots of split necks...I haven’t tried to replicate his load as I have a tendency to choose heavier bullets. I’ll go check if they are on the lands...


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Here is another reason to really check out any rifle before you fire it. My hunting buddy used to do all the scope sighting in for a local gun shop. I was with him one day helping out and there was a brand new Remington 700 rifle with 243 Winchester marked on the barrel and was bought as a 243 Winchester. The ammo that was sent with it was Federal 100 gr blue box 243 Winchester. He always shot the rifles at 25 yards then looking through the scope while holding the rifle steady in the rest would dial the scope from where the bullet hole was down to the aiming point before moving to the 100 yard shooting. He fires the shot from the rifle and the bullet hole in the target was key holed. He then takes a look at the crown on the rifle thinking that maybe it had gotten damaged and caused the bullet key hole. When he looked he noticed that the hole look much larger than 6mm. He took a look at the case he had just fired and it looked just like a 308 Winchester case. Turned out the rifle WAS A 308 Win but had been marked 243 Winchester.

Back in the 1980's I was also in a gun shop once when UPS delivered some guns that had been ordered. One was a Smith and Wesson semi auto in 9mm. When the shop owner removed the pistol from it's box to display as his safety habit was he racked the slide to check it. Low and behold when he did this a Winchester silver tip HP round went flying across the counter. When the pistol was test fired somebody left it loaded and shipped it.
 
Ive measured the different bullets I load for 7mm RM with a Hornady OAL gauge. Turns out Partitions seated to SAMMI length are in the rifling by .012". E-Tips have an oal of 3.435" to touch the lands. Speer Hot Cors touch the lands at 3.264" oal. Then Ballistic Tips are .020" off the lands at SAMMI length of 3.290". The longest of which are ELDX's, at almost a full 3.5" to touch the lands. I'll never take SAMMI or manual OAL guidelines for granted again. The ogive on all bullets differ and so does the throat of every individual rifle. It's a lesson I'll not forget, and thank God for the luck he blessed me with that day at the range. The BT's shot great during break in for the barrel that day however. Just be careful guys. It would sadden me to hear one of you lost a rifle, or worse, life or limb. Keep your focus.
 
Had a similar experience, sort of, last week when I loaded some Speers for my 250 Savage. Loaded to the same over all length as my BT load, the Speer hot core's had rifling marks on them. Didn't stick in the chamber, but close....so

Kept seating the bullets deeper until no marks were visible, then went deeper still. I don't remember the exact measurement, but the COAL was still longer than the COAL listed in the Speer manual for that bullet. I understand that this will be fine, but does this mean that one shouldn't work from the COAL for given load in a manual, no matter what? CL
 
Hi CL,

Yes, don’t trust SAAMI at face value.
There are short chambered guns out there. Just takes one machine operator to short stroke a reamer for the chamber.

As mentioned OGive matters a lot to what you can safely do. The 300 WSM I mentioned has a stiff bolt, I’m piling it like crazy and working it empty to loosening up. If the bolt is nice and light, you should be able to feel the contact if the bullet hits the lands, but to your question a number of us have run into chambers and OAL in manuals not being ok.


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Interesting and "good" comments. Every time I change to a different make bullet in my .300WM I measure by coating and unloaded round with a magic marker and running it slowly into the chamber to see if it strikes the rifling. You can tell usually by the bolt stiffness in closing. The other consideration is magazine length which might make the decision for you.
 
Good stuff here guys!

Joe - glad you and the rifle came out okay. And thank you for sharing the experience!

Guy
 
I just happen to remember this one also. Was loading 139 gr Hornady Interlocks in a 7mm Rem mag for deer hunting a good number of years ago. The rifle was one of the most accurate rifles out of the box I have ever seen. It was a Rem. 700 Stainless with black synthetic stock. Back then I was measuring only the COAL and did not have a ogive comparator. I was foolishly also loading within 5 thousands of the lands using the old split case neck method of finding the lands with a bullet. Went hunting one morning and climbed into my ladder stand and then loaded up the rifle in the dark. By about 11:30 a.m. I had seen no buck to shoot and the coffee I drank at breakfast needed to come out of me BAD and I also had lunch in the truck so I decided to go to the truck for a brake. When I go to extract the round out of the chamber to climb down out of the stand all that comes out is the case and the lots of the powder pours down into the action. The bullet is stuck in the bore. I did not have a cleaning rod or any tools in my truck to remove the bullet or clean the powder out. Yep you guessed it. On my way back to my truck with a rifle incapable of being fired out walks old mister big buck and stands broad side 50 yards away in the path and just looks at me then walks off unconcerned. Another fellow on the other side of the farm kills him a few days latter. Turned out that I had loaded some rounds from another lot number of bullets and the ogive to nose of the bullet measurement was different than the other bullets I had been shooting. I was jamming the new bullets into the lands. I had to drive 28 miles to where I was parking my camper to get my cleaning stuff and fix the rifle and then drive 28 miles back to hunt that afternoon. Learned a few lessons out of this. NEVER load a round closer than 10 thousands to the lands in a hunting rifle, double check your components, always have a cleaning kit in the truck and always carry a pistol capable of killing a deer in case something happens to your rifle.
 
Speer Hot Cor bullets seem to end up with a shorter OAL for the calibers I use them in. As an example in my 270 Win. The Speer bullets seated at 3.210” are .020” off the lands. Nosler Ballistic Tips are .020” off the lands at a OAL of 3.340”. Both are 130 grains, shoot really well, are within 1 grain of charge weight with IMR4831, but bullet design and ogive location require different finished load dimensions. I really find it very interesting how projectiles of the same caliber and weight can have such a wide variation of lengths which they contact the lands. Those measurements will also be different in two identical rifles.
 
Joe, not that what you say and learned isn’t good, but split necks is a brass issue, not a pressure issue in my opinion. If they’d been over pressure you’d have had extremely hard bolt lift and marks all over your case heads. Just my thoughts is the brass was either worked excessively or a bad batch myself.

It’s not necessarily horrible to stuff bullets in the lands and most 7 Rem data is pretty conservative in my experience.

Just my thoughts on it. Still, always good to work up carefully but the split necks make me wonder much more about the brass condition than your load.
 
SJB358":3dfiodx9 said:
Joe, not that what you say and learned isn’t good, but split necks is a brass issue, not a pressure issue in my opinion. If they’d been over pressure you’d have had extremely hard bolt lift and marks all over your case heads. Just my thoughts is the brass was either worked excessively or a bad batch myself.

It’s not necessarily horrible to stuff bullets in the lands and most 7 Rem data is pretty conservative in my experience.

Just my thoughts on it. Still, always good to work up carefully but the split necks make me wonder much more about the brass condition than your load.
It was never fired Winchester brass. I think I may give them a call. If they balk, I’ll pull them and anneal the cases. Then see if that helps. Thanks for the insight.
 
Agree with Scotty, the few times I've run into split necks was with aged brass reloaded many times without ever being annealed. I now anneal every 3 loadings or so and end up tossing brass because it's reached the end of it's life primarily because of finally getting too thin ahead of the case web, not split necks.

Far as bullets being jammed, I agree, check every bullet type and weight being loaded in every rifle. I've run into that numerous times.....if a person were to just load at saami max length, or even book length used for that particular bullet, in some rifles that will be jammed pretty significantly. Not an issue if using starting loads and working up, but I don't like jammed bullets in hunting loads.

Probably why some people run into "hot" factory loads. That ammo would likely not appear hot in 10 other rifles.
 
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