Chambering problems?

[Bigcat_hunter]

I just got back from the range from shooting a Sako 75 300 wsm for the first time. About one out of every three rounds was hard to fully close the bolt and to open it after firing? With one bullet I could not even close the bolt. This was a mild load but I had one case neck split on new brass. I full length sized new brass so I am wondering if it is a problem with the rifle or the ammo.

I am shooting 200 grain accubonds seated .020 off the lands using a 300 win mag magazine in a long action. I bought an after market mag so I could run the long bullets but that should not have any thing to do with the bolt closing.

 

[onesonek]

Well BH, my first thought is, that somehow your seating dies got out of adjustment so that you're seating longer and the bullets are engaging the lands. This would make chambering hard and could raise pressure enough to cause the split. But generally .020" off the lands should be great plenty to account for minor variations of the seater and ogive relationship on individual bullets.
Other thoughts include the possiblity of crooked throat. Or an out of round neck in the chamber it self.
I would double check the seating depth, and chamber each finished round off the press. If one or more won't chamber, try and measure where the difference's may be. A tight chamber neck and uneven neck thickness may be another possibility, making chambering difficult. If all else fails, make a chamber cast and see if there is anything unusual in it's measurements. On the neck split, there is the possibility of it just being a bad piece that had no visual signs. ,,,Another thought,,,
Did you work up to that moderate load also? just asking. If it's a tight chamber specially in the neck, uneven brass may be the whole problem
Having to force a round in a tight chamber can or even a tight chamber alone can raise pressures above manual listings. I have a couple custom chambers in standard rounds that I'm just over starting data, but running faster than max velocity listed. I can't go any near max data charge wieghts without running into major pressure problems. The fix may be as simple as turning the necks.
Sorta rambling thoughts, but I think you may get my drift.

Dave

 

[rick smith]

FL die is not adjusted correctly. If you have any new brass that hasn't been sized or fired, make a dummy round w/o sizing and try it in your rifle. Try some factory loaded rounds. Do your fired, unsized cases fit? Is the Sako a CRF?Rick.

 

[Big Squeeze]

I just got back from the range from shooting a Sako 75 300 wsm for the first time. About one out of every three rounds was hard to fully close the bolt and to open it after firing? With one bullet I could not even close the bolt. This was a mild load but I had one case neck split on new brass. I full length sized new brass so I am wondering if it is a problem with the rifle or the ammo.

I am shooting 200 grain accubonds seated .020 off the lands using a 300 win mag magazine in a long action. I bought an after market mag so I could run the long bullets but that should not have any thing to do with the bolt closing.

................As stated above, the problem may lie in one or more of several areas.

Before going to the range, SAFELY chamber and close the bolt for all your reloads to test for ease or difficulty in feeding and chambering.

I had the same problem with my 300 WSM. Wouldn`t feed properly with some and had some bolt closing difficulties.

Re-check your sizing die and make sure that the top your shellholder barely touches the bottom of your re-sizing die. THEN, turn your die clockwise, down another 1/4 to a 1/3rd turn. This will assure as best as possible, that your case is getting fully sized AT THE SHOULDER.

That was my problem! Screwing the die down a little more solved it.

Now, I have no feeding or chambering problems......I`d start there first!

 

[Antelope_Sniper]

sounds like your brass might be too long and need trimming.

 

[Bigcat_hunter]

FL die is not adjusted correctly. If you have any new brass that hasn't been sized or fired, make a dummy round w/o sizing and try it in your rifle. Try some factory loaded rounds. Do your fired, unsized cases fit? Is the Sako a CRF?Rick.

Yes its a CRF. Why?

 

[rick smith]

Some CRFs have to be fed from the mag box to work correctly but not all of them.Rick.

 

[onesonek]

sounds like your brass might be too long and need trimming.

Good note, I forgot mentioning it as possiblity. As it's just one of those natural steps for me to trim new brass after sizing. Thus assuring the same length, and square necks.

Dave

 

[steve4102]

Does your once fired FL sized brass chamber without a bullet seated?

How did you set up your FL dies?

Do you have a case gauge like the Stony Point (Hornady) that you can take a "Head to Shoulder" measurement before and after sizing?

My guess is that your are having the same problem as many 300WSM handloaders, not getting the shoulders bumped back during re-sizing.

 

[old #7]

sounds like your brass might be too long and need trimming.

+1
Long brass will definately chamber hard and if the bolt is realy tight when closing it might crimp the neck and cause your pressure problem.

 

[Ol` Joe]

Does your once fired FL sized brass chamber without a bullet seated?

How did you set up your FL dies?

Do you have a case gauge like the Stony Point (Hornady) that you can take a "Head to Shoulder" measurement before and after sizing?

My guess is that your are having the same problem as many 300WSM handloaders, not getting the shoulders bumped back during re-sizing.

Very common cause of hard chambering. I`d look here 1st.

 

[Bigcat_hunter]

Well, I bought some factory ammo and it does not cycle smooth either. Easier than my hand loads but the bolt is hard to close and open. I think I will have my gunsmith look at it.

 

[NTM]

I had the same problem with my tikka. A guy on another forum suggested grinding a couple of thousands of an inch off of my shell holder as the shoulders were probably not getting bumped back enough. Tried it and it worked great.

 

[Antelope_Sniper]

In addition, Tikka's have a tendancy to have a tight throat....I think it's part of the reason they shoot so good....but could also contribute to the types of problems we are discussing.....