I bought two different kind of .308, 165 gr Game Kings.

.308 - 165 gr Game King Soft point
.308 - 165 gr Game King hollow point.

Same load data, right? wrong! I loaded up a few for test firing in my Rock River 308. Medium loads, 39.5 of IMR 3031. COL 2.8" (Thanks Tony )

Take a look at this picture. You are looking for difference in ogive from the hollow point to the soft point, same weight bullet.



Can you see the drastic difference? Maybe not noticeable in the picture, but it is a completely different shape.

Since I load these in a AR platform 308. I do not notice that the bullet is hard to chamber since the bolt is slamming it about 1/8 to 3/16" into the lands because every round that I had chambered so far, I fired. (with great accuracy I might add) 5/8" and 3/4" groups below!



The problem comes when I go into the field and try to clear the gun. The Bullet gets stuck in the barrel. I figure it was a fluke, don't worry about it.

Clean the gun, scrub the chamber with a chamber brush. Happens a second time. Ok, something isn't right. I chamber one in my bolt action, it's tough to chamber, same thing. It gets lodged in the barrel. All bullets have about a 3/16" mark where it has been jammed up into the lands.

All the bullets were pulled free from the case and pushed back down with a cleaning rod.

All bullets were loaded to 2.8" COL
No lube used in the neck of the case (I wash all the cases before loading and after tumbling). SO no chance of them slipping forward when the bolt closed.

The ogive is way farther forward on the hollow points.

So, anyone load these? Anyone seen this same problem? The clear answer is to load them shorter, about 3/16" shorter to be exact. Just found it very odd that the a bullet with the same name would have such a drastically different shape.

One had an empty pocket one has a lead tip. They can't be the same shape. Something has to give. Sometimes it is length. Next time ogive.

Simply need to check each bullet type.

I check every bullet/barrel combination for max. possible COL and take this into consideration when setting up a load.
Sierra's loading data is just a rough first hint at what could be a successful load. Nothing more and nothing less.

I happen to load the very same bullets in 7x64 and .30-06, i.e. the Sierra .284 SP/HP GK 160 g and the .308 SP/HP 165 g in .30-06. HP's being the hardest of the 2, I use them if Wild boar may be encountered in the area I hunt Roedeer. I love the way both bullets configurations use the same load, shoot as accurately and to the same POI ; to put it shortly, they are 100% interchangeable. Now, coming to the COL. Unless I misunderstood, I believe you seat both at the same "measured" OAL. I don't, I seat them at the same ogive/lands position, using a Stoney Point OAL gauge. This is quite different if you take into account that bullets coming from the very same box often vary in length. Therefore, measuring COL is pointless and the only reliable data comes from bullet to land contact.

Yup, I had the same problem. I think I was shooting the 168gr Matchking in my Steyr. The gun really loved the load I was using so I tried loading up some 165gr Gameking HP's for hunting. The Gamekings wouldn't chamber, I had to shorten them up a little. You could see where the rifling was cutting the jacket on chambering.

quote:

I believe you seat both at the same "measured" OAL. I don't, I seat them at the same ogive/lands position, using a Stoney Point OAL gauge. This is quite different if you take into account that bullets coming from the very same box often vary in length. Therefore, measuring COL is pointless and the only reliable data comes from bullet to land contact.

I don't use a Stoney just a home brew method but COL is something I worry about when it won't fit in my mag box or my AR mags.

quote:

I believe you seat both at the same "measured" OAL. I don't, I seat them at the same ogive/lands position, using a Stoney Point OAL gauge. This is quite different if you take into account that bullets coming from the very same box often vary in length. Therefore, measuring COL is pointless and the only reliable data comes from bullet to land contact.

COL on a bullet like this would be much more uniform than a lead tip bullet that can easily have a deformed lead tip. But, you are right. Its the ogive that determines the COL in any bullet.

I was shocked that two, seemingly, almost identical bullets would vary in construction by so much.

The funny thing is when I looked at them, my first thought was "Those are loaded way too long!" I measured them, rechecked the data ... yep 2.8" COL. Ok, I guess it's fine.

Wendell

You need to seat the 165 HPBT Gamekings to an OAL of 2.735.

At this length they have fed in every different kind of 308 rifle, even all the Paramilitary semiautos, including AR 10's, and they also have chambered in all 308's without contacting the rifling. No extraction problems.

The powder charge is 39.5gr of IMR 3031.

In fact I used this load to kill 2 deer and 3 pigs just this deer season.

I killed 2 pigs at 85 yards with one shot. I let them get lined up, pig No2 was 4 feet or so behind pig No1. Both went right down at the shot.

I have found the Sierra 165 gr HPBT Gameking to be an excellent hunting bullet for the 308.
I have never recovered one and I have killed game as far as 550 yards, an antelope, with it.

Also Andre is correct.

Sierra told me personaly that the HPBT Gamekings are a tougher bullet than the same weight and calibre lead tipped spitzers.

The main reason I reload is to make a more accurate round for a particular rifle.

Before I ever start...I take two measurements for that rifle for EACH DIDFFENT BULLET I shoot in it.

1) max OAL to feed from the magazine
2) max length for the ogive to touch the lands. (don't have to have a Stoney Point to do this)

Then...those are my guidelines to produce the best shooting load for each.

With out knowing those to things...I would feel I was loading in the dark.

I've been reloading for semi-auto rifles for 45 years now. Anytime I try a new bullet I cover the bullet with dry ink and loosely seat it into the case I close the bolt on the "dummy" round and then slowly extract the case/bullet. The bullet will be pushed back into the case and show rifling marks on the ogive of the bullet.
I back off the bullet ( deeper seat) about .002-.003 and set the die. I also Always use a Lee or other crimp die on any semi-auto rifle. If the bullet was to become jammed by crud or unburnt powder, it will not not stay in the chamber,but will be ejected with the case. When the crimp is done right, you do no damage to the bullet. I use this technique with my 1,000 yards loads. It works for me.
I load 7.62x51 and .308 a lot every year for my rifles. All are diff by just a little, and that is all that it takes to cause a problem. By doing the bullet "fit" test, I never have had any FTF/FTE problems.
Hope this info helps.

Lvm and Rapidrob's methods are both just as valid. The advantage of an OAL gauge (Stoney Point, Sinclair, etc.) is that it is more convenient and speeds up the works.

quote:

The problem comes when I go into the field and try to clear the gun. The Bullet gets stuck in the barrel. I figure it was a fluke, don't worry about it.

I am the fan of transfers and standards. I have the Sinclair/Hornady maximum overall length gage with the modified cases, the tool with the cases does not make good transfers because because the modified cases come in one size and the necks have reduced bullet hold: Bullet hold, referred to as being neck tension by reloaders.

I drill the primer pocket/flash hole to a diameter that will accommodate a cleaning rod or dowel. I seat a bullet, then chamber. after chambering I push the bullet out of the case until it contacts the rifling. Once the bullet contacts the rifling I remove the dowel then the test case. Choices, I can use the test case as a transfer by placing the case in the shell holder and then raise the ram. After raising the ram I adjust the seating die to the test case. First adjust the die to the case to crimp or adjust the die off the case not to crimp then secure the lock nut. Next adjust the seating plug down to the bullet, after contact with the bullet measure the height of the seating stem above the die. record the height above the stem as .000” off the lands. If the reloader chooses to seat the bullet off the lands .040” lower the seating stem .040”.

The concept of zero. The bullet is going to contact the rifling between the two diameters, for the 30/06/308 the two diameters are .308’'” and .300”, that is .004” when centered. A reloader that can measure the distance from the contact point between the bullet and rifling and can the can measure the distance from the case head to the rifling once/ It is possible to make a test case for each bullet, the test case is used to set-up the seating die.

Modified cases compared to fired cases. Not often but it is possible to add the difference in length between the case form the shoulder to the head of the case and the chamber when measured from the should to the bolt face. If the difference is not considered the bullet will be off the lands a distance equal to the difference in length between the case and chamber when measured from the usual places.

Then there is the firing pin, it is said to hit the primer then it drives the case, powder and bullet forwards until the shoulder of the case seats against the shoulder of the chamber without busting the primer? On my next P/U I want my rear bumper made of the same material primers are made from.

F. Guffey

quote:

Originally posted by N E 450 No2:
Wendell

You need to seat the 165 HPBT Gamekings to an OAL of 2.735.

Thanks. I will try that length. I have been using the 39.5 gr of 3031 since you told me that load a few years ago. Both my 308's like that load a lot.

Wendell

I have shot or seen that load shot in over 100 308/7.62 rifles over the years.

I am not going to say it is the best load in every 308, but I have never seen ANY 308 that did not shoot that load real good.

See you in Dallas at DSC.

I started using that load around 1975 or so and even today, with all the new different powders, I have never seen any reason to change it as my General Purpose 308 load.

Also this same load works great with the Sierra 168 gr Matchking, the 165 gr Nosler Ballsitic Tip, and the 165 gr Nosler Partitions.

I seat these bullets out to just under 2.800, so they fit in any Paramilitary 20 round magazine.

quote:

Originally posted by N E 450 No2:
Wendell

I have shot or seen that load shot in over 100 308/7.62 rifles over the years.

I am not going to say it is the best load in every 308, but I have never seen ANY 308 that did not shoot that load real good.

See you in Dallas at DSC.

I started using that load around 1975 or so and even today, with all the new different powders, I have never seen any reason to change it as my General Purpose 308 load.

It gives me an 1" in my bolt and in my Rock River. It's been a great load for all the 165s I put through it. Thanks again for sharing.

Every round of hunting ammo I take to the woods is cycled through my rifle before I leave the house. I thought this was a common practice.

Wendell, I think your misconception was purely on the name "Gameking". That doesn't mean anything more in the Sierra world other than that it is a boattail hunting bullet as oppossed to a "Prohunter" that is flat base. It has nothing to say about the ogive being the same. Heck, the "Palma" bullets both have different ogives with the same 155 weight, only the new 155 has the Palma ddeignation, but that is what the old 155 was designed for as well.

Bottom line is you have to measure every time.