milling temps!

Yes, this is common if you aim to grind fine flour on typical small stone high speed mills.

In lieu of a peer reviewed report, the MockMill FAQ has (or had -- I no longer see the FAQ) this to say about temperature:

The flour temperature depends on the amount and fineness of the grist: the finer, the warmer!

We work with a scientist who stores almost all known mills from around the world in his university laboratory and whose milling results he regularly tests. He bakes with the flours heated differently by the milling. His result: Up to a temperature of 60 ° C (140 F) he could not find any disadvantages for the baking process in any of the tests. The bread volume and taste also remained the same up to a temperature of 60 ° C during milling.

Search for "milling temperature" on this site and you will find this question has come up repeatedly with a range of opinions on the subject.  I believe your temperature of 130 F is high enough to kill enzymes, which will ultimately get killed in the bake anyway.  Some people point out that killing these enzymes may change behavior of the flour during bulk fermentation.  It has also been pointed out that the temperature inside the mill may be higher than what you measure in your bowl.

If you are milling on a fine setting you can restrict intake to lower the temperature or try to use two stage coarse-to-fine milling to reduce temperature: (1) coarse cracked grain; then (2) fine flour.  Anecdotally, this does seem to help.  Some people recommend cooling the grain prior to, or even in between, milling stages.  I have read this may impact bran separation.

If there is any ill effect of baking flour heated to 130 F, I believe it will be very subtle in relation to most of the more fundamental parameters we are aiming to optimize (temperature, timing, hydration, etc.). 

Mentioned above, you could refrigerate or freeze the berries before milling.

This 1962 Master's Thesis from KC State is interesting.  No doubt there is a more recent source somewhere. There is quite a lot of info there, and perhaps others more familiar with milling and grain science can comment more authoritatively, but it seems heating the wheat in ranges similar to the temperature you are reporting, with and without moisture, may improve baking quality (within limits).

Some Effects of Cold, Warm and Hot Wheat Conditioning on the Milling and Baking Characteristics of Wheat

Walter Dale Eustace

Master's Thesis from KC State in 1962

A few relevant passages:

Kent-Jones (23), {24} , (25) in determining the effects of heat on wheat, found that heating dampened wheat to a temperature of 110 F for twenty-four hours produced no changes in baking quality or chemical properties. No changes were observed at 135 F for two hours but for six hours slight changes were noticed. Heating at 135 °F for twenty-four hours greatly increased the strength* Sour odors developed after standing for several hours* Wheat heated to 160°F for one and one-half hours to two hours before conditioning gave flour of increased strength

...

In teats with German domestic wheat, Kuhl (27) improved the gluten with heat treatment up to 62°C to 65 C for up to two hours.

...

Becker (2) investigated the effects of hot conditioning on the gluten of wheat. Temperatures of $6*C to 6o°C were used.  Farinograph showed that the higher temperatures strengthened the dough

...

The baking teats and farinographs showed heat damage for samples heated to 60 C for twelve hours, 70°C for fifteen minutes or one-half hour, and 90*C for five minutes. Cold soaking treatments gave the best loaf of bread

...

Geddea (15) found that as the moisture of the wheat is in- creased, the critical temperature, where baking quality is impaired, is lowered.

Tests conducted by Lindberg (26) found the critical temperature for the impairment of baking quality to be 50 C at a wheat moisture of 25 per cent, 55 °C at a wheat moisture of 20 percent and 65 °C for a wheat moisture of 15 percent.

I have a Mock Mill and grind all my own grain. I wondered about temps at and following milling. I usually grind with the stones set closely as the Mock Mill instruction booklet says to use. 

I found that the temp did go up to 120-130 but it’s floating out into a wide open plastic two qt bowl and the temp dropped very quickly , within seconds to double digits .

Absolutely no effect on any baking I have done with the Mock Mill ground grains and I have been using it a number of years now on a weekly basis. 

I once heated flour in the microwave as it had been stored in the fridge and I wanted to take the chill off quickly.  I obviously got it too hot. Ruined the flour and impossible to bake with. Destroyed some essential component. 

I don’t think you have any concern. 

I do grind coarsely then follow it with a fine grind.  After sifting, I run 2-3 consecutive passes on the sifted larger particles (or alternately whiz them in a coffee grinder until wonderfully fine). Yes the temp has risen on these parts that are ground last but the bread has improved a lot with the finer particles (reduced most of the pastiness) even if there are negative effects of high temps. 

I put the berries in a ziploc and freeze for an hour minimum before milling. Big difference in temp. of flour. Easy.