Powder question

[BJ]

I just started reloading and have a question. I loaded some 7mm mag shells with nosler 140 grain ballistic tips with 61 grains of imr 4350 powder. When I shot them I noticed the barrel heated up more than normal. When I shoot factory loads the barrel does not get as hot. I checked the spent shells and they showed no sign of excessive pressure
Does 4350 burn hotter than other powders?

 

[DrMike]

BJ,

Welcome to the forum. Undoubtedly you will gather a wealth of information from a vast data bank as you read and interact with the people that post here. They are a great group, and represent multiplied years of experience with hand loading.

Ambient temperature may have been higher than at other times when you have shot. It is possible that you shot at a different rhythm which meant more shots per unit time. Or it is possible that you misinterpreted the sensation of heat with your hand. The temperature differential from one powder and another is negligible in the real world.

I really don't know if this applies in your situation, but generally, it is a good idea to give time between shots and time between groups to permit the barrel to cool down. This is not only to avoid eroding the throat quicker than is necessary, but it permits a relatively consistent base line for data when you are attempting to generate data. In short, it eliminates (or at least tempers) one variable.

Best of luck as you continue to load for your 7 RM.

 

[huntnfool]

I agree with DrMike.

I was at the range yesterday (92-98 degrees with 85 % humidity) testing loads in my 270 WSM. I allowed at least 3 minutes between shots. I thoroughly clean after every 6-9 shots. I use Shooters Choice and a few Montana Extreme products.

I also do not load much past the middle of the powder chart. My rifle seems to like mid-weight powder charges. I am currently testing IMR 4350, RL 19, IMR 7828 SSC, H-4350, H-4831 SC, and Ramshot Magnum.

So far my rifle (Savage Model 14 Classic) likes nearly every powder at a certain grain weight(+/- .5 to 1 grain at the middle of the load chart). Different rifles like different combinations. I am loading Nosler Ballistic Tips and Accubonds in 130, 140 and 150 grain bullets with CCI 250 primers and Barnes TSX 130's with the same primer.

Welcome to the forum. I am new here myself. As DrMike stated, there is a ton of knowledge here and people seem quite helpful and willing to share their experiences.

DrMike, I envy where you live. I would like to come to Northern BC and hunt sometime.

Paul

 

[JD338]

BJ

Welcome to the forum, glad you are here.

DrMike is spot on.
Try to space your shots about 5 minutes apart with the action open to allow for cooling. You can also use a rag with rubbing alcohol to enhance cooling. Wipe on the rubbing alcohol and let it evaporate. It will help pull the heat out of your barrel.

What kind of accuracy are you getting with IMR4350?

JD338

 

[DrMike]

I envy where you live. I would like to come to Northern BC and hunt sometime.

Huntnfool,

I treasure some great memories hunting mule deer and javalina around Terlingua. I did my doctorate at the medical school in Dallas and pipe lined along the ship channel, which gave me a few opportunities to hunt and fish while in Texas. To be certain, there is some fine hunting up here, but the hunting in many of the states, primarily due to the efforts of sportsmen throughout the USA, has certainly taken a dramatic change for the best.

 

[Ridge_Runner]

I just started reloading and have a question. I loaded some 7mm mag shells with nosler 140 grain ballistic tips with 61 grains of imr 4350 powder. When I shot them I noticed the barrel heated up more than normal. When I shoot factory loads the barrel does not get as hot. I checked the spent shells and they showed no sign of excessive pressure
Does 4350 burn hotter than other powders?

could be your factory loads are loaded with ball powder, which has a much lower flame temp than extruded type single base powders. here is an example
If I load my 7mm stw up with 86 gr of H-1000 behind a nosler 140 BT which clocks 3550 fps, fire 3 shots in 2 minutes, the barrel is too hot to hold in your hand.
Take the same rifle and load up a 160 AccuBond with 94 gr of WC872 will run 3340 fps, fire 3 shots in 2 minutes the barrel is barely warm.
The ball powders are easier on the throat IMO, but with that comes a heat sensativity issue. I have learned to deal with the temp. sensative powders in an effort to extend barrel life in my overbore cartridges.

But like has been said, the cooler you keep your barrel the better it is for the throat.
RR

 

[BJ]

My shots were spaced out at least five minutes between each shot. When I would get up after each shot I would grab the barrel and thats when I noticed the temperature difference of the barrel. I started out with the factory loads to check my zero. I then shot three of my handloads and noticed the temp difference. I quit shooting the handloads due to temperature concerns. As for accuracy with the 4350 powder I have not used it enough to get conclusive results. I am going to load up some shells for my 243 with the 4350 and see if i get the same results.

 

[OU812]

Some powders heat the barrel more than others, by what margine who knows. I would not be concerned with the barrel heat difference between factory and handloads.

One thing to keep in mind is when you fired the factory rounds at the start the barrel was as cool as it was going to get for that day. Waiting 5 minutes between shots is a good idea but that 5 minutes will not allow the barrel to cool to the point it was when you started. Barrel temp builds with time as it heats much quicker than it cools.

With handloads my first 2-3 fouling shots the barrel is still fairly cool, beyond that it get warm real quick.

 

[DrMike]

Five minutes between shots will not permit the barrel to cool down to ambient temperature. It is certainly sufficient to avoid overheating the barrel, but the barrel will retain measurable heat energy generated during combustion of the powder. Burn temperature of powder is relatively consistent across a variety of burn rates. The greater factor in determining heat retention is related to powder volume and starting temperature of the barrel when a particular shot is fired. Since there is residual heat in the barrel, raising the temperature above air temperature, the amount of heat retained will always increase with each successive shot unless the barrel actually cools to the identical temperature of the air surrounding it.

 

[Greg Nolan]

All the above.
My take is that you may want to chronograph your factory vrs. handloads and see if there isn't a velocity difference. Factory stated velocities are sometimes wishfull thinking and the faster the bullet the more friction etc. etc. There is some difference in powder burn tempreture also, especially with some newer factory loads that use powders unavailable to handloaders.
If your loads aren't showing pressure signs there will be no problem unless you need to shoot a lot of rounds fast a lot of the time.
IMR 4350 is my favorite powder for anything in it's burn rate range.
Good Shooting
Elkhunt :grin:

 

[JD338]

BK,

61.0 grs IMR4350 is a starting load so I wouldn't be concerned. The important thing is to allow for cooling between shots.

IMR4350 is a classic powder, been around for a long time and is a proven performer.
If you do not get the results you are looking for, I would like to suggest you try RL 22. You should get higher velocity as well as excellent accuracy with the 140 gr BT.

Keep us posted on your load development.

JD338

 

[FOTIS]

BJ

Welcome to the forum, glad you are here.

DrMike is spot on.
Try to space your shots about 5 minutes apart with the action open to allow for cooling. You can also use a rag with rubbing alcohol to enhance cooling. Wipe on the rubbing alcohol and let it evaporate. It will help pull the heat out of your barrel.

What kind of accuracy are you getting with IMR4350?

JD338

I agree totally!!!